American society of zoologists. Annual meeting; New York city New York December 28 through 30 1960. Officers Proceedings Program and List of Titles Abstracts of Papersкод для вставкиСкачать
AMERICAN SOCIETY OF ZOOLOGISTS Officers and Representatives f o r 1959-60 President . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .EMIL WITSCHI Past President . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . VICTOR C. TWITTY President EEect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C. LADDPROSSER Secretary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GAIRDNER B. MOMENT Treasurer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . JERRYJ. KOLLROS Program Oflicer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . RAYL. WATTERSON Divisional Officers Animal Behavior: Chairman . . . . . . . . . . . . . . . . . . . . . . . . . .LESTERARONSON Vice Chairman . . . . . . . . . . . . . . . . . . . .WILLIAMC. YOUNG Secretary . . . . . . . . . . . . . . . . . . . . . . . . . MARTIN W. SCHEIN Comparative Endocrinology: Chairman . . . . . . . . . . . . . . . . . . . . EMIL WITSCHI Secretary . . . . . . . . . . . . . . . . ..HOWARD A. BERN Program Officer . . . . . . . . . . . .ALBERT WOLFSON Acting for AUBREY GORBMAN Comparative Physiology : Chairman . . . . . . . . . . . . . . . . . . . . . . C. LADD PROSSER Chairman Elect . . . . . . . . . . . .THEODORE H. BULLOCK Program OfFicer . . . . . . . . . . . . .BRADLEYT. SCHEER Secretary-Treasurer . . . . . . . . . . . .F. JOHNVERNBERG Developmental Biology : Chairman . . . . . . . . . . . . . . . . . .CLIFFORDGROBSTEIN Vice Chairman . . . . . . . . . . . . . . . . . .JAMES D. EBERT Program Officer . . . . . . . . . JOHN W. SAUNDERS, JR. Secretary-Treasurer . . . . . . . . . . . .BEATRICEMINTZ Vertebrate Morphology : Organizing Committee: Chairman, BOBB SCHAEFFER RICHARD J. BALDAUF (Election of Divisional HARVEYFISHER Officers will take place PERRYW. GILBERT at New York) ALFREDS. ROMER Executive Committee (In addition to the six general officers and the Chairman of each of the Divisions) LIBBIE H. HYMAN. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . to DONALDP. COSTELLO. . . . . . . . . . . . . . . . . . . . . . . . . . .to LEWIS H. KLEINHOLZ . . . . . . . . . . . . . . . . . . . . . . . . . . .to EDGARZWILLING. . . . . . . . . . . . . . . . . . . . . . . . . . . . to EDGARJ. BOELL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .to KENNETH W. COOPER. . . . . . . . . . . . . . . . . . . . . . . . . . . .to serve serve serve serve serve serve through through through through through through 1960 1960 1961 1961 1962 1962 Representative of the Society in the Division of Biology a n d Agriculture of the National Research Council THEODORE L. JAHN............................ .to serve through 1962 Representatives of the Society o n the Council of the American Association for the Advancement of Science DAVXD W. BISHOP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ALBERT WOLFSON............................. .to serve through 1960 .to serve through 1961 Representative of the Society on the Board of Governors of the American Institute of Biological Sciences W. GARDNER LYNN ............................. to serve through 1960 Representative of the Society on the Biological Stain Commission HAROLD W. BEAMS ............................. .to serve through 1962 Representative of the Society on the Board of Trustees of the American Type CuZhire Collection RICHARDP. HALL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .to serve through 1960 (Unless otherwise specified, all terms of office end on December 31st.) TABLE OF CONTENTS Page Officers . . . . . . . . . . . . . . . . . . . . . . . . . 299 Synopsis of Program . . . . . . . . . . . . . 302 Proceedings . . . . . . . . . . . . . . . . . . . . . 303 Page Program . . . . . . . . . . . . . . . . . . . . . . . . Abstracts ....................... Index to Abstracts . . . . . . . . . . . . . . . 305 329 392 SYNOPSIS OF PROGRAM Although the Society meets officially only on Wednesday through Friday. we are co-sponsoring certain general symposia on Tuesday as well. and therefore have included details about them in our program . Page TUESDAY MORNING. DECEMBER 27 . Symposium: Life under extreme conditions. I Cells and tissues . . . . . . . . . . . . . Symposium: Modem aspects of population biology. I . . . . . . . . . . . . . . . . . . . . . . 307 307 TUESDAY AFTERNOON. DECEMBER 27 . Symposium: Life under extreme conditions. I1 Plants and animals . . . . . . . . . . Symposium: Modem aspects of population biology. I1 . . . . . . . . . . . . . . . . . . . . . . Symposium: Famous Zoologists .......................................... Meeting: Policy Committee. American Society of Zoologists . . . . . . . . . . . . . . . . . 307 308 308 308 TUESDAY EVENING. DECEMBER 27 Meeting: Executive Committee. American Society of Zoologists WEDNESDAY MORNING. DECEMBER 28 . . . . . . . . . . . . . . . 308 . Symposium: Life under extreme conditions. I11 Human studies . . . . . . . . . . . . . . Symposium: Evolution and dynamics of vertebrate feeding mechanisms . . . . . . . Session A: Comparative Physiology. I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Session B: Comparative Endocrinology. I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Session C: Animal Behavior and Sociobiology. I Early experience . . . . . . . . . . . . . Session D: Developmental Biology. I . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 308 309 309 310 310 311 WEDNESDAY AFTERNOON. DECEMBER 28 Symposium: Evolution of sex .............. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Session E: Comparative Physiology. I1 Special session on muscle . . . . . . . . . . . . . SessionF: Animal Behavior and Sociobiology. 11 . . . . . . . . . . . . . . . . . . . . . . . . . . . Business Meeting: Division of Comparative Physiology . . . . . . . . . . . . . . . . . . . . . . . Business Meeting: Division of Developmental Biology . . . . . . . . . . . . . . . . . . . . . . . 312 312 313 313 314 . . WEDNESDAY EVENING. DECEMBER 28 Business Meeting: Division of Comparative Endocrinology . . . . . . . . . . . . . . . . . . . Panel Discussion: Research opportunities for undergraduates . . . . . . . . . . . . . . . . . M A S General Meeting: Presidential address and reception . . . . . . . . . . . . . . . . . . 314 314 314 (Continued on next page) 301 302 AMERICAN SOCIETY O F ZOOLOGISTS SYNOPSIS OF PROGRAM Page THURSDAY MORNING. DECEMBER 29 Symposium: Spermatozoan motility. I . . . . . . . . . . . . . . . . . . . . . . . . . ........... Symposium: Physiology of molluscs. I . . . . . . . . . . . . . . . . . . . . . . . . . . ........... Session G: Comparative Endocrinology. I1 . . . . . . . . . . . . . . . . . . . . . . . ........... Session H: Animal Behavior and Sociobiology. I11. Sexual behavior . . . . . . . . . . . ........... Session I: Developmental Biology. I1 . . . . . . . . . . . . . . . . . . . . . . . . . . ........... Session J: Vertebrate Morphology. I . . . . . . . . . . . . . . . . . . . . . . . . . . . Demonstrations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ........... Organizational Meeting: Division of Vertebrate Morphology . . . . . . . . . . . . . . . . . . 314 315 315 315 316 317 317 319 THURSDAY AFTERNOON. DECEMBER 29 Symposium: Spermatozoan motility, 11 . ...................... Symposium: Submicroscopic cellular stru ction . . . . . . . . . . . . . . . . . (Unsolved Problems of Biology, 1960) Session K: Comparative Endocrinology, I11 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Session L: Animal Behavior and Sociobiology, IV Sexual behavior and communication . . . . . . . . . . . . . . . . . ...... Session M: Vertebrate Morphology, I1 . . . ...... Demonstrations ....................... .......... ...... BusinessMeeting: Section F, AAAS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Business Meeting: American Society of Zoologists . . . . . . . . . . . . . . . . . . . . . . . . . . . . 318 318 318 319 319 317 320 320 THURSDAY EVENING. DECEMBER 29 Zoologists’ Dinner and Vice Presidential Address. AAAS. Section F . . . . . . . . . . . . AAAS-3 iologists’ Smoker . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 320 320 FRIDAY MORNING. DECEMBER 30 Symposium: Spermatozoan motility. I11 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Symposium: Physiology of molluscs. I1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Symposium: Teaching animal behavior. I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Session N: Comparative Physiology. I11 Physiology of arthropods . . . . . . . . . . . . . Session 0: Developmental Biology. I11 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Demonstrations ......................................................... . 320 321 321 321 322 317 FRIDAY AFTERNOON. DECEMBER 30 Symposium: Spermatozoan motility. Iv . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Symposium: Teaching animal behavior. I1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Session P: Invertebrate Zoology. Parasitology and Protozoology . . . . . . . . . . . . . . . Session Q: Comparative Physiology. IV Physiology of arthropods .............. SessionR: Genetics and Cytology ........................................ Session S: Experimental Biology .......................................... Demonstrations ......................................................... . 323 323 323 324 324 325 317 Proceedings of The Fifty-Seventh Annual Meeting of the American Society of Zoologists OKLAHOMA STATE UNIVERSITY STILLWATER, OKLAHOMA August 29-31, 1960 INTERIM BUSINESS MEETING The interim business meeting of the Society was called to order by the President, Professor Emil Witschi, after the Society dinner at which he had delighted the members with his colorful and informative presidential address, “The Itinerant Zoologist.” Appointments. President Witschi announced the appointment of the following Society representatives: Dr. T. L. Jahn to the Division of Biology and Agriculture of the National Research Council, Dr. D. W. Bishop and Dr. A. Wolfson to the Council of the American Association for the Advancement of Science, Dr. W. G. Lynn to the Board of Governors of the American Institute of Biological Sciences, and Dr. H. W. Beams to the Biological Stain Commission. Dr. Harry Charipper will be our local representative in New York. XVI International Congress of Zoology. The President then called upon the newly chosen Secretary-General of the XVI International Congress of Zoology, Dr. Gairdner Moment, to make a brief statement. The Congress is sponsored by the National Academy of Sciences-National Research Council and will be held in Washington, D.C. from August 21-27, 1963. Dr. Alfred Romer was elected President of the Congress and Dr. Alexander Wetmore, Treasurer. All the air-conditioned facilities of both the Sheraton-Park and Shoreham Hotels, where the zoologists met at Christmas in 1958, have been reserved. The program is still in the formative state, but it is expected that there will be provision for major addresses, invited symposia, and contributed papers. The last previous Congress, in London in 1958, drew 1,800 mem- bers from over 60 countries. The first of these congresses was held in Paris in 1889 and only one has ever previously been held outside of Europe. That was in Boston in 1907. The present occasion should provide a magnificent opportunity for North American zoologists to meet and exchange views with their colleagues from overseas. All correspondence should be addressed to 2101 Constitution Avenue, Washington 25, D. C. New Division and New Members. The Executive Committee, in accordance with the new policy, had met the day before the scientific sessions began. The committee authorized the formation of a Division of Vertebrate Morphology on the basis of a petition from an organizing committee consisting of Drs. Bobb Schaeffer (Chairman), J. Baldauf, H. Fisher, P. Gilbert, and A. S. Romer and bearing 96 signatures. The following members of the executive committee were present: Drs. E. Witschi (serving both as President of the Society and as Chairman of the Division of Comparative Endocrinology), C. L. Prosser (serving both as President Elect and as Chairman of the Division of Comparative Physiology), G. B. Moment, J. J. Kollros, R. L. Watterson, L. Aronson, J. W. Saunders, Jr. (for C. Grobstein), E. Zwilling, and E. J. Boell. Absent were: Drs. V. C. Twitty, K. W. Cooper, D. P. Costello, L. H. Hyman, and L. H. Kleinholz. Immediate entrance into membership was authorized for approximately 90 new members with doctor’s degrees, and a number of special cases lacking the doctorate were deferred until the New York meeting. Resolutions. President Witschi entertained motions of appreciation from the 303 304 AMERICAN SOCIETY OF ZOOLOGISTS Society to be transmitted to the President and Administration of Oklahoma State University, to Professor Roy W. Jones, our local representative, and to Dr. Hiden Cox of the AIBS for their respective roles in making our meetings so successful. He also presented a resolution of gratitude to Dr. H. B. Goodrich and the retiring members of the Policy Committee for their years of dedicated and fruitful labors. All motions were passed unanimously. The resolution of appreciation to the Policy Committee follows : ‘The Executive Committee and the entire membership of the American Society of Zoologists do hereby express their genuine appreciation for the work which Hubert B. Goodrich and the Policy Committee have achieved. The vigorous growth of the Society in recent years both in numbers and in usefulness is in large measure attributable to the devotion, vision, and expertness with which they have worked. Dr. Goodrich and the Committee have earned the lasting gratitude of our Society.” The Policy Committee then consisted of Drs. J. B. Buck, C. Grobstein, F. Moog, T. Park, C. L. Prosser, A. G. Richards, and C. S. Thornton, in addition to Dr. H. B. Goodrich. The President then called on Dr. Raymond L. Taylor of the AAAS to make a brief announcement about the New York meeting at which the Hotel Commodore will be our headquarters. Room F of the Commodore has been designated as committee room for the Society during the New York Meeting. Refresher Courses. The President announced that the Refresher Course planned for next summer will deal with Comparative Physiology and for the summer after that with Comparative Anatomy. He also explained that the Executive Committee after several years of careful study believes that the time has come when the Society can publish and control its own journal, to be called The American Zoologist. It will contain the material now published in two issues of The Anatomical Record and in addition our various symposia and refresher courses. There has been a persistent and lively demand for this material. The journal will be explained in detail through a letter to the membership and a mail vote on its establishment requested. The Executive Committee has thoroughly modernized the constitution which will also be presented to the membership for a mail vote. The urgent need of Biological Abstracts for volunteer abstractors and the rewards of such work were presented. National Legislation. President Witschi urged each member to write his senator and congressmen in favor of the Magnuson Bill (S2692) for the support of oceanographic research. The bill may not be perfect in all respects, but it is a great deal better than nothing and is essential unless the United States is to be far outdistanced in this field by other nations. In regard to proposed national antivivisection legislation (S3570) which would greatly complicate animal research, he sharply protested that it is discriminatory and that it is aimed at research and investigators, whereas any other U.S. citizen remains free of similar surveillance. In the interest of research he urged that even the appearance of neglect or mistreatment of animals, including frogs and fishes, should be carefully avoided in our laboratories. Future Meetings. It seems evident that, as a general rule, the Society will hold two national meetings a year, one with the AIBS at the end of the summer, and one with the AAAS immediately after Christmas. The scheduled meeting places for the AIBS are as follows: Purdue University, 1961; Oregon State University, 1962; University of Massachusetts, 1963; and University of Colorado, 1964. The corresponding meeting places for the AAAS are: Denver, 1961; Philadelphia, 1962; Milwaukee, 1963; Boston, 1964; Berkeley, 1965 (tentative). Dr. Witschi pointed out the advantages of more meetings on the Pacific Coast. The Executive Committee, recalling a vote of the Society favoring occasional meetings by ourselves, solicits invitations, particularly for the post-Christmas meeting of 1962, when it is believed a meeting in the far South might be desirable. PROGRAM Fifty-Eighth Annual Meeting of the AMERICAN SOCIETYOF ZOOLOGISTS DECEMBER 28 through 30, 1960 New York City, New York A brief synopsis of the program is given on pages 301 and 302 of this issue. Two hundred and twenty-five papers will be read or presented by demonstration in 37 sessions including 7 symposia. Additional papers will be co-sponsored on two other symposia. Fifty-one papers will be presented by title only. Animal Behavior and Sociobiology. In addition to a two-session symposium on Teaching Animal Behavior (organized by E. B. Hale), this Division will hold 4 sessions of contributed papers. A business meeting will not be held. Comparative Endocrinology. Emil Witschi has organized a one-session symposium on Evolution o f Sex. Three sessions will be devoted to contributed papers. A business meeting will be held. Comparative Physiology. This Division will present a two-session symposium on the Physiology of Molluscs (organized by R. Boolootian) and a special session of contributed papers on the comparative physiology of muscles (organized by C. Ladd Prosser) in addition to three other sessions of contributed papers. A business meeting will be held. Developmental Biology. Three sessions will be devoted to contributed papers and a business meeting will be held. Vertebrate Morphology. A one-session symposium on Evolution and Dynamics o f Vertebrate Feeding Mechanisms has been organized by Perry W. Gilbert and Bobb Schaeffer. Two sessions will be devoted to contributed papers. An organizational meeting will be held. Symposium on Spermatozoan Motility. David W. Bishop has organized a special 4-session symposium on Spemzatozoan Motility with the aid of a grant from the National Institutes of Health, U.S.P.H.S. The principal theme of the symposium is the physicochemical basis of the mechanism of motility in these flagellated cells. The program is broad in scope and is directed toward an integration of several relevant research disciplines. Miscellaneous Sessions. Three additional sessions of contributed papers will be held, one devoted to Invertebrate Zoology, Parasitology and Protozoology, one to Genetics and Cytology and one to Experimental Biology. Demonstrations. The room containing the demonstrations will be open specsed hours on Thursday and Friday. Panel Discussion. WiUiam Etkin has organized a panel discussion on Research Opportunities for Undergraduates for the Education Committee of The American Society of Zoologists. Zoologists’ Dinner and Vice Presidential Address. Thursday Evening. Dr. Viktor Hamburger of Washington University will present the vice presidential address for Section F, AAAS. Business Meeting of the American Society of Zoologists. The annual business meeting will be held Thursday afternoon. AAAS-Biologists’ Smoker. A smoker for biologists will be held at the Commodore Hotel and will be co-sponsored by Sections F and G of AAAS and The American Society of Zoologists. Co-sponsored Symposia. The Society will co-sponsor a three-session symposium on Life under Extreme Conditions: Part I, 305 306 AMERICAN SOCIETY OF ZOOLOGISTS Cells and Tissues (organized by A. Cecil Taylor); Part 11, Plants and Animals (organized by Charles P. Lyman); Part 111, Human Studies (organized by J. P. Marbarger). It will also co-sponsor a two-session symposium on Modern Aspects of Population Biology (organized by Reed C. Rollins), a one-session symposium on Submicroscopic Cellular Structure and Function (Organized by Barry Commoner and Viktor Hamburger), and a one-session symposium on Famous Zoologists (organized by Carl L. Hubbs and George W. Wharton). For the past several meetings chairmen and speakers have cooperated t o keep the programs exactly on the published time schedule. This has been an important feature in the success of the meetings and this policy should continue. If a speaker fails to appear, the free time may be used for further discussion or for a brief recess. Any speaker or presiding officer who finds a t the last minute that he cannot attend the meeting should notify either the Program Offlcer of the Division concerned or Ray L .Wattemon, Program Offlcer of the Society. LIST OF TITLES Titles are arranged in the order o f presentation. Papers t o be presented by title only are listed last. T h e abstracts, which follow the list o f titles, are arranged alphabetically by the name of the first author. TUESDAY MORNING, DECEMBER 27 Symposium : L i f e under extreme conditions, I. Cells and tissues. 9 :00 A.M. (No abstracts) Organized by A. Cecil Taylor, Rockefeller Institute for Medical Research. Co-sponsored by Sections F and G, AAAS and The American Society of Zoologists. West Room 18, Biltmore Hotel A. CECIL TAYLOR, presiding 1. MERYMAN,HAROLD.Effects of extreme cold on vertebrate cells. 2. HALVORSON, HALVOR.Effects of extreme temperatures and dessication on bacteria. 3. MARSLAND,DOUGLAS. High pressure studies on living cells. Symposium : Modern aspects of population biology, I. 9 :30 A.M. Organized by Reed C. Rollins, Gray Herbarium, Harvard University, for the American Society of Naturalists. Co-sponsored by the American Society of Zoologists, the Ecological Society of America and The Society for the Study of Evolution. Music Room, Biltmore Hotel REED C. ROLLINS,presiding DUNN,L. C., Columbia University. Big and little populations: an amateur’s excursion. (Presidential address, American Society of Naturalists.) G. EVELYN,Yale University. Niche specificity and diversity with HUTCHINSON, special reference to plankton. SLOBODKIN,L. B., University of Michigan. The relation between laboratory and field investigations in population ecology. TUESDAY AFTERNOON, DECEMBER 27 Symposium : L i f e under extreme conditions, II. Plants and animals. 2:OO P.M. (No abstracts) Organized by Charles P. Lyman, Harvard Medical School. Co-sponsored by Sections F and G, AAAS and The American Society of Zoologists. West Room 18, Biltmore Hotel CHARLESP. LYMAN,presiding 2: 00 4. PHILPOTT, JANE,Duke University, Structural adaptations of woody plants to arid environments. (40 min.) 307 308 AMERICAN SOCIETY OF ZOOLOGISTS 2:46 3:30 5. BLISS, LAWRENCE, University of Illinois. Adaptations of Arctic and Alpine plants to environmental conditions. (40 min.) 6. HART,J. S., National Research Council, Ottawa, Canada. Seasonal acclimatization in mammals and birds. (40 min.) 4:16 7. BARTHOLOMEW, GEORGEA., University of California, Los Angeles. Adaptations of reptiles, birds and mammals to high environmental temperatures. (40 min.) Symposium: Modern aspects of population biology, 11. 2 :00 P.M. Music Room, Biltmore Hotel EARLL. GREEN,presiding LEWIS,HARLAN, University of California, Los Angeles. Experimental sympatric populations of Clarkia. ROLLINS,REED C., Gray Herbarium, Harvard University. Phenotypic response to compatibility shift in wild populations of Leavenworthia. WILSON, E. O., Harvard University. Some recent theoretical contributions from zoogeography. MACARTHUR,ROBERTH., University of Pennsylvania. Population effects of natural selection. Symposium: Famous zoologists. 2: 00 P.M. Organized by Carl L. Hubbs, Scripps Institute of Oceanography and George W. Wharton, University of Maryland, for the Society of Systematic Zoologists. Co-sponsored by the American Society of Zoologists and Section F, AAAS. A series of anecdotal talks and recollections about some famous recently-deceased zoologists. Biltmore Suite, Biltmore Hotel CARL L. HUBBS,presiding ROMER, ALFRED E., Museum of Comparative Zoology, Harvard University. Thomas Barbour. (30 min.) L., U. S. National Museum. Leonhart Stejneger. (30 min.) SCHMITT, WALDO MILLS, HARLO B., Illinois Natural History Survey. Stephen A. Forbes. (30 min.) MILLER,ALDEN H., University of California, Berkeley. Joseph Grinnell. (30 min. ) WHARTON, GEORGEW., University of Maryland. A. S. Pearse. (30 rnin.) HUBBS,CARLL., Scripps Institute of Oceanography. Additional comments on A. S. Pearse. Meeting: Policy Committee of The American Society of Zoologists. 3: 00-5: 00 P.M. Room F, Commodore Hotel TUESDAY EVENING, DECEMBER 27 Meeting: Executive Committee of The American Society of Zoologists. 8 :00 P.M. Room F, Commodore Hotel WEDNESDAY MORNING, DECEMBER 28 Symposium : Life under extreme conditions, IIZ. Human studies LIST OF TITLES 309 9:OO A.M. (No abstracts) Organized by J. P. Marbarger. Co-sponsored by Section F, AAAS and The American Society of Zoologists. Windsor Ballroom, Commodore Hotel J. P. MARBARGER,presiding 8. STRUGHOLD, HUBERTUS. Introduction and resume of problem. 9. HITCHCOCK, FREDA. The effect of extreme pressure changes on the human being. 10. HARDY, JAMES D. The responses of man to extreme conditions of hyperthermia. 11. HORVATH, STEVEN M. The effect on the human being of extreme conditions of hypothermia. Symposium : Evolution and dynamics of vertebrate feeding mechanisms. 9 :00 A.M. Organized by Perry W. Gilbert, Cornell University, and Bobb Schaeffer, American Museum of Natural History, for the Division of Vertebrate Morphology. East Ballroom, Commodore Hotel PERRYW. GILBERT,presiding 9:oo 9:20 9:40 9:55 10:15 10:35 10:55 11:15 11:35 ROBERTH., Chicago Natural History Museum. Feeding 12. DENISON, mechanisms of Agnatha, Acanthodii and Placodermi. (15 min.) U. S. Fish and Wildlife Service. Dynamics of STEWART, 13. SPRINGER, the feeding mechanism in sharks. (Introduced by Perry W. Gilbert) (15 min.) 14. SCHAEFFER, BOBB, American Museum of Natural History. The origin of the holostean feeding mechanism. (10 rnin.) 15. ROSEN,DONNE., Florida State Museum and University of Florida. The jaw of cyprinodontiform fishes, a pre-acanthopterygian experiment in protractility. (15 min.) C., University of Chicago. Feeding mechanisms : 16. OLSON,EVERETT Crossopterygians, amphibians, primitive reptiles. ( 15 min.) 17. GANS,CARL,University of Buffalo. The feeding mechanism of snakes: its possible evolution. (15 rnin.) ROBERTI., San Francisco State College. Feeding adapta18. BOWMAN, tions in Galbpagos finches. (15 min.) 19. DAVIS,D. DWIGHT,Chicago Natural History Museum. The feeding mechanism in mammals. (15 rnin.) 20. ROMER, ALFRED S., Harvard University. Concluding comments. Session A: Comparative Physiology, 1. 8:50 A.M. West Ballroom, Commodore Hotel K. SCHMIDT-NIELSEN, presiding 8:50 21. ROCKSTEIN,MORRIS AND ARNOLDFINKEL,New York University School of Medicine and Marine Biological Laboratory. Stellarin, a photosensitive pigment from the dorsal skin of the starfish, Asterias forbesi. (15 min.) 310 AMERICAN SOCIETY OF ZOOLOGISTS 9:lO 9:30 9:50 1O:lO 10:30 10:50 11 :10 22. PROSSER, C. LADD,Bermuda Biological Station and University of Illinois. Mechanical responses of sponges. (15 min.) 23. GILBERT,PERRYW. AND STEVEND. DOUGLAS, Cornell University. Electrocardiography of free-swimming sharks. (Motion picture, 15 min.) 24. HAWLEY, PHILIP L., G. EDGAR FOLK, JR. AND MARYA. FOLK,State University of Iowa. Influence of magnesium on intact and isolated rodent hearts in hypothennia. (Motion picture, 15 min.) 25. HUDSON,JACKW., University of California, Los Angeles. Water requirements and thermoneutrality in the antelope ground squirrel, Citellus Zeucurus. ( 15 min.) 26. GOLDBERG, ERWIN, CHARLESNORMANAND I. D. PORTERFIELD, West Virginia University. Studies on the metabolism of fowl spermatozoa. (15 min.) 27. NORMAN,CHARLES, ERWIN GOLDBERG, I. D. PORTERFIELD AND C. E. JOHNSON, West Virginia University. Prolonged survival of human sperm and other mammalian sperm in chemically defined media at room temperatures. (15 rnin.) 28. GOLDSMITH, DALEP. J. AND E. S. NASSET,University of Rochester School of Medicine and Dentistry. Gastric acid secretion in control and thyroid-fed frogs. (Introduced by C. W. Casperi) (15 min. ) Session B : Comparative Endocrinology, I. 9: 00 A.M. Windsor Terrace, Commodore Hotel BERTASCHARRER, presiding 9:oo 9:20 9:40 1o:oo 10:15 10:30 10:50 11 :10 BERTA AND MARIANNE VON HARNACK, Albert Einstein 29. SCHARRER, College of Medicine. Castration effects in the insect, Leucophaea maderae. (15 min.) 30. EVANS,LLEWELLYN T., Research Laboratory, Jaffrey Center, N. H. Neuroendocrine mechanisms in courtship of a turtle. (15 rnin.) 31. MACINTYRE, M. NEIL, Western Reserve University School of Medicine. The biologic activity of the inductors of fetal gonadal differentiation in the rat. ( 15 min.) 32. LEATHEM, JAMES H., Rutgers University. Reproductive organ responses to estrogen in rodents. (10 min.) C., JR. AND SHEILAL. LYTLE,Louisiana State Uni33. KENT,GEORGE versity. Decidual cell responses following exogenous prolactin in uterine-traumatized hamsters. (10 min.) 34. KENT, HARRYA., JR., University of Georgia. A glycostatic factor from the fallopian tube of the golden hamster. (15 min.) 35. BRAUN-CANTILO, JORGE A., GILLESLA ROCHEAND JOHN H. LAWR E N C E ~University of California, Berkeley. Conversion of testosterone to estrogens in the human female. (15 min.) 36. LANGAN, WILLIAMB., New York Medical College and the Food and Drug Research Laboratories. Ovulation-inducing action of steroid hormones in Rana pipiens. (10 min.) Session C: Animal Behavior and Sociobiology, I. Early Experience 9: 00 A.M. (In collaboration with the Section of Animal Behavior and Sociobiology of the Ecological Society of America.) 311 LIST O F TITLES Windsor Court, Commodore Hotel 9:oo 37. 9:20 38. 9:40 39. 1o:oo 40. 10:20 41. 10:40 42. 11 :00 43. 11 :20 44. 11 :40 45. HELENBLAUVELT, presiding KRAMER, SOL, State University of New York. Early predatory behavior in praying mantids. ( 15 min.) CAMPBELL, B. A. AND J. R. PICKLEMAN, Princeton University. The imprinting object as a reinforcing stimulus. (15 min.) GOTTLIEB, GILBERT,Duke University. Developmental age as a baseline for determining the critical period in imprinting. (15 min.) TOBACH, ETHEL,L. VROMAN, G. TURKEWITZ AND T. C. SCHNEIRLA, American Museum of Natural History. Infantile experience with specific visual stimuli as related to later differential approach responses in rats. (15 min.) Upstate Medical Center BLAUVELT, HELENAND A. ULRICHMOORE, in Syracuse and Cornell University. Effects of early social experience on aggressive play in young goats. (Motion picture, 15 min.) MOORE,A. ULRIC AND MARVIN AMSTEY, Cornell University. Animal hypnosis (tonic immobility) considered as a parameter of behavior in distinguishing between a group of normal and abnormal (experimental) lambs and kids. (15 min.) FULLER,JOHN L., Jackson Memorial Laboratory. Effects of graded and delayed experience on behavioral development in puppies. (15 min.) HARLOW, HARRYF., University of Wisconsin. The development of infant-infant affectional responses in monkeys. (Motion picture, 15 min.) (No abstract) BERNSTEIN, IRWINS., Laboratories of Primate Biology, Orange Park, Florida. Response to nesting materials by wild-born and captive-born chimpanzees. (15 min.) Session D : Developmental Biology, I . 9:00 A.M. Parlors B and C, Commodore Hotel 9:oo 46. 9:20 47. 9:40 48. 1o:oo 49. 10:20 50. 10:40 51. HOWARD L. HAMILTON, presiding ARGYRIS, THOMAS S. AND BERTIE F. ARGYRIS,Syracuse University. The differential response of epidermis and hair follicles to subcutaneously transplanted Ehrlich ascites tumor. (15 min.) GIBLEY, CHARLES W., JR. AND HOWARD L. HAMILTON, Iowa State University. Action of two pyrimidines and a riboside on develop ment of the down feather. (15 min.) WHITTAKER, J. R.,Yale University. An in vivo analysis of tyrosinase function and melanin formation in ascidian embryos. (Introduced by Patricia F. Knight) (15 min.) BRICK, IRVING, New York University. Quantitative effects of pituitary activity on melanophore development in Ambystoma maculatum. (Introduced by H. Clark Dalton) (15 min.) MOYER,FRANK,Johns Hopkins University. Some effects of pigment mutations on the fine structure of mouse melanin granules. (Introduced by C. L. Markert) (15 min.) BAKER,WILLIAMK.,University of Chicago. Genetic control over the somatic differentiation of eye pigments in Drosophila. (15 min.) AMERICAN SOCIETY OF ZOOLOGISTS 312 11:00 11 :20 11:40 12:00 B. AND D. F. POULSON, Yale University. Transfer of 52. SAKAGUCHI, the “sex-ratio” condition from Drosophila willistoni to D. melanogaster. (Introduced by G . E. Hutchinson) (15 min.) D. F. AND B. SAKAGUCHI, Yale University. Evidence 53. POULSON, concerning the nature of the “sex-ratio” agent in Drosophilu. (15 min.) 54. GILL, KULBIR S., Yale University. Developmental physiology of five female-sterile mutants in Drosophila melanogaster. (Introduced by Alexander Petrunkevitch) (15 min.) MAX,Albert Einstein College of Medicine. Neuro55. HAMBURGH, embryology of “Reeler,” a neurological mutation in mice. (10 min. ) WEDNESDAY AFTERNOON, DECEMBER !28 Symposium: Evolution of sex. 2 :00 P.M. (No abstracts) Organized by E d Witschi for the Division of Comparative Endocrinology of The American Society of Zoologists. Co-sponsored by Section F, AAAS, the Division of Developmental Biology and The Genetics Society of America. Windsor Ballroom, Commodore Hotel EMIL WITSCHI,presiding 2:oo 2:35 3:OO 3:26 4:05 4:46 56. ZINDER,NORTON D., The Rockefeller Institute. Genetic exchange in bacteria and bacteriophages. (30 min.) 57. RUSSELL, LIANEB., Oak Ridge National Laboratory. Genetics of mammalian sex chromosomes. (20 min.) 58. OHNO,SUSUMU, City of Hope Medical Center. The sex chromatin: facts and interpretation. (20 min.) 59. POLANI,PAULE., Guy’s Hospital, London. Sex chromsomes and sex aberrations in man. (35 min.) 60. LORAND, JOYCE BRUNER, Northwestern University. Epigenesis of sex determination. (40 min.) 61. WITSCHI,EMIL, State University of Iowa. Comments and perspectives. (15 min.) Session E : Comparative Physiology, 11. Comparative physiology of muscle. 2:OO P.M. Special program arranged by C. Ladd Prosser for the Division of Comparative Physiology. East Ballroom, Commodore Hotel C. LADDPROSSER, presiding 2:OO 2:20 2:40 3: 00 62. DE VILLAFRANCA, GEORGEW., Smith College. Some properties of the contractile proteins from frog and horseshoe crab muscle. (15 min.) 63. KOMINZ,DAVID R.,National Institutes of Health. The comparative biochemistry of tropomyosin, paramyosin and the 3 S component of myosin. ( 15 min.) 64. HAYASHI, TERU,Columbia University. Actin and its bound nucleotide. (15 min.) (No abstract) 65. SZENT-GYORGYI, ANDREWG., Marine Biological Laboratory. Proteins of molluscan muscles. (15 min.) LIST OF TITLES 3:20 3:40 4:oo 4:20 4:40 313 66. JOHNSON, WILLIAMH., University of Illinois. Evidence for a dual mechanism for tonic contractions in molluscan muscles. (15 rnin.) 67. MCCANN,FRANCES V., Dartmouth Medical School. Comparative electrophysiology of fibrillar muscle. (15 min.) EDWARDG., University of Connecticut. Length68. BOETTIGER, induced changes in the active state of fibrillar muscle. (Introduced by C. Ladd Prosser) (15 min.) 69. WILSON,DONALD, Yale University. Neuromuscular transmission in annelids and cephalopods. (15 min.) (No abstract) 70. MARSHALL,JEANM., Harvard Medical School. Relationship between transmembrane potentials and contractile tension in uterine smooth muscle. (15 rnin.) Business Meeting Division of Comparative Physiology of The American Society of Zoologists. 5: 15 P.M. East Ballroom, Commodore Hotel Session F: Animal Behavior and Sociobiology, II. 2:OO P.M. (In collaboration with the Section of Animal Behavior and Sociobiology of The Ecological Society of America) Windsor Court, Commodore Hotel C. R. CARPENTER, presiding 2:oo 2:20 2:40 3:OO 3:20 3:40 4:OO 4:20 4:40 LESTER R. AND RONALD HERBERMAN, American Museum 71. ARONSON, of Natural History. Persistence of a conditioned response in the cichlid fish, Tilapia macrocephala, after forebrain and cerebellar ablations. (15 min.) G.TURKEWITZ AND T. C. SCHNEIRLA, 72. VROMAN,LEO,E. TOBACH, American Museum of Natural History. Physiological effect of preweaning manipulation in two strains of rats. (15 rnin.) HELENAND A. ULRIC MOORE, State University of New 73. BLAUVELT, York and Cornell University. Aggressive behavior in the social organization of goats and sheep. (Motion picture, 15 min.) 74. DINGLE,HUGH,University of Michigan. Flight and swimming reflexes in giant water bugs. (15 &.) 75. BROWER,LINCOLNP., Amherst College. Ecological similarity and cannibalistic interaction in the Monarch and Queen butterfiies, Danaus plexippus and D . berenice. (Motion picture, 15 min.) 76. BROWER,JANEVAN ZANDT,Amherst College. The reactions of Southern toads (Bufo tenestris) to honeybees (Apis mellifica) and their Syrphid fly mimics (Eristalis sp.). (Motion picture, 15 rnin.) 77. GRIFFO, JAMES V., JR., Fairleigh Dickinson University. A study of homing in the cotton mouse, Peromyscus gossypinus. (15min.) 78. CARPENTER,C. R., Pennsylvania State University. Population analysis, group composition and behavior of howler monkeys (Alouatta palliata) of Barro Colorado Island in 1959. (15 min.) 79. KUHINKA, ERNESTM., Dickinson College. Consumer behavior: inner-orientation of population in a functional area. (15min.) 314 AMERICAN SOCIETY O F ZOOLOGISTS Business Meeting Division of Developmental Biology of The American Society of Zoologists. 5: 15 P.M. Windsor Court, Commodore Hotel WEDNESDAY EVENING, DECEMBER 28 Business Meeting Division of Comparative Endocrinology of The American Society of Zoologists. 8 :00 P.M. Parlors B and C, Commodore Hotel Panel Discussion : Research opportunities for undergraduates. 9:oo P.M. Organized by William Etkin, Albert Einstein College of Medicine, for the Education Committee of The American Society of Zoologists. Co-sponsored by Section F, AAAS. Windsor Terrace, Commodore Hotel WILLIAMETKIN, presiding 9:oo Panel discussions. Panelists : FULLER, JOHN L., Jackson Memorial Laboratory. PHILLIPS, LYLEW., National Science Foundation. SHAW,EVELYN,American Museum of Natural History. STONE,DAVID, Worcester Foundation for Experimental Biology. 9:45 Discussion from the floor. The AAAS General Meeting for all societies: Presidential address and reception. 8:00 P.M. Grand Ballroom, Commodore Hotel THURSDAY MORNING, DECEMBER 29 Symposium: Spermatozoan motility, I. 9:00 A.M. Organized by David W. Bishop of the Carnegie Institution of Washington, Department of Embryology. Supported by a grant from the National Institutes of Health, U.S.P.H.S. Co-sponsored by The American Society of Zoologists and Section F, U S , and the Society of General Physiologists. No abstracts. Proceedings to be published in full at a later time. Windsor Ballroom, Commodore Hotel 9:OO 10:16 11:16 presiding H. BURRSTEINBACH, 80. Lorn ROTHSCHILD, University of Cambridge. Sperm movement, problems and observations. 81. F. D. CARLSON, Johns Hopkins University. A theory of the survival value of motility. (Paper no. 82 has been withdrawn.) Discussion. LIST OF TITLES 315 Symposium: Physiology of molluscs, I . 9:OO A.M. Organized by R. Boolootian, University of California, Los Angeles, for the Division of Comparative Physiology. Grand Ballroom, Commodore Hotel K. M. WILBUR,presiding 9:oo 9:40 10 :20 11:00 83. SEGAL, EARL,Rice University. Acclimation in molluscs. (30min.) 84. VAN WEEL,P. B., University of Hawaii. Comparative physiology of digestion in molluscs. (30 min.) 85. ALLEN,KENNETH, University of California, Los Angeles. Nitrogen metabolism in the rnollusca. (30 min.) 86. CARRIKER, MELBOURNE R., University of North Carolina. Comparative functional morphology of the boring mechanism in boring gastropods. (30 min.) Session G: Comparative Endocrinology, 11. 9:00 A.M. Windsor Terrace, Commodore Hotel A. BERN, presiding HOWARD 9:oo 9:20 9:40 1o:oo 10 :20 10:40 11:00 11:20 87. SCOTT,GEORGET. AND LEWIS K. NADING,Oberlin College and Marine Biological Laboratory. The relative effectiveness of phenothiazine tranquilizing drugs causing the release of MSH in the frog. (15 min.) RONALD R., BARBARA JEAN NOVALES AND STEPHENH. 88. NOVALES, ZINNER,Northwestern University. Further studies on ionic factors influencing intermedin action on frog skin. (15 min.) PAULF. AND E. KNOBIL,Harvard Medical School. The 89. BRANDE, effect of simian and bovine growth hormone on the incorporation of amino acids into protein. (15 min.) 90. BLIVAISS, BEN B., RUSSELL0. HANSON,HELEN KUTUZOV AND GERALDRIEGER, Chicago Medical School. Pituitary ICSH in C5,BBR male mice treated with estradiol. (15 min.) H. M., AND C. H. SAWYER, University of California Med91. RADFORD, ical Center, Los Angeles and Veterans Administration Hospital, Long Beach. EEG changes in the rabbit rhinencephalon related to pituitary activation by intraventricular norepinephrine. ( 15 min.) 92. WOLFSON,ALBERT,Northwestern University. Mechanism of photoperiodic regulation of reproductive and migratory rhythmicity in birds. (15 min.) 93. DEROOS,ROGER,University of California, Berkeley. The corticosteroids of bird adrenals investigated by in vitro incubation. (Introduced by S. Nandi) (15 min.) DEROOS,University of California, A. AND CAROLYN 94. BERN,HOWARD Berkeley. The corticosteroids of the California sea lion (Zalophus californianus) adrenal incubated in vitro. (15 min.) Session H : Animal Behavior and Sociobiology, I l l . Sexual Behavior. 9 :00 A.M. (In collaboration with the Section of Animal Behavior and Sociobiology of The Ecological Society of America) AMERICAN SOCIETY OF ZOOLOGISTS 316 9:oo 95. 9:20 96. 9:40 97. 1o:oo 98. 10:20 99. 10:40 100. 11 :00 101. 11 :20 102. 11 :40 103. 9:oo 104. 9:20 105. 9:40 106. 1o:oo 107. 10:20 108. 10:40 109. 11 :00 110. 11 :20 111. Windsor Court, Commodore Hotel EVELYNSHAW,presiding BROWER,LINCOLNP. AND FLORENCE P. CRANSTON, Amherst College and Harvard Medical School. A quantitative study of the courtship behavior in the Queen butterfly, Danaus berenice (Cramer). (Motion picture, 15 min.) PICCIOLO, ANTHONYR., University of Maryland. Sex discrimination in species of Colisa and Trichogaster. (15 min.) KRAMER, SOL,State University of New York. Color changes correlated with parental behavior in cichlid fish. (15 min.) GREENBERG, BERNARD,Roosevelt University, Spawning and parental behavior in female pairs of the jewel fish, Hemichromis bimaculatus Gill. (Motion picture, 15 min.) PHILLIPS,RICHARDE. AND D. FRANKMCKINNEY,Cornell University and Delta Waterfowl Research Station. Effect of testosterone on occurrence of some duck displays. (15 min.) KLOPMAN, ROBERTB., Cornell University. A motivational interpretation of the greeting display in geese. (15 min.) HALE,E. B., Pennsylvania State University. Role of head height in releasing sexual versus fighting behavior in turkeys. (15 min.) FICKEN,ROBERTW., Cornell University. Some aspects of behavioral evolution. (Motion picture, 15 min. ) DILGER,WILLIAMC., Cornell University. The evolution of agonistic, precopulatory and nest-building behavior in the African parrot genus Agapornis. (15 min.) Session I : Developmental Biology, 11. 9:00 A.M. Parlors 3 and C, Commodore Hotel MAC V. EDDS,JR., presiding WEISS,Albert Einstein College ROSENBAUM, R. M. AND CHARLES of Medicine. Autolytic activity during limb regeneration in Triturus: a histochemical approach. (15 min.) CAIRNS,JOHNM., Roswell Park Memorial Institute. Depth of penetration of growth-stimulating factor from apical ectodermal ridge into the limb bud mesoderm of the chick. (15 min.) MARY T. AND JOHNW. SAUNDERS, JR., Marquette GASSELING, University. Further observations on the reciprocal influence of ectodermal and mesodermal factors in the origin of limb symmetry in the chick embryo. (15 min.) F. E. AND HOWARD HOLTZER, University of PennsylSTOCKDALE, vania School of Medicine. The formation of multinucleated myotubes. (15 min.) LYTLE,CHARLESF., THOMAS ELSDALE AND CLARENCE M. FLATEN, Indiana University and Tulane University. Time-lapse studies of amphibian blastomeres in culture. (Motion picture, 15 min.) PECK,DAVID,Johns Hopkins University. Effects of tissue organization upon the stability of synthetic properties of embryonic cells in vitro. (Introduced by M. S. Steinberg) (15 min.) CROWELL,SEARS,Indiana University. Non-regulative differentiation in the thecate hydroid, Campanularia. (15 min.) G., Princeton University. The development of diFANKHAUSER, ploid and triploid embryos of Triturus (Diemyctylus) viridescens grafted under the skin of adults of the same species. (15 min.) 317 LIST OF TITLES c. VAN DE KAMER, University of CO~Orado and the Rijksuniversiteit, Utrecht, Netherlands. Some cytological and histochemical considerations of the amphibian pineal organ. (15 min.) 113. WOOD,PAULINEJ., University of Washington. Histodifferentiation in the palate of the human embryo. (15 min.) E. AND J. 11:40 112. KELLY, DOUGLAS 12:OO Session J: Vertebrate Morphology, I. 9:00 A.M. East Ballroom, Commodore Hotel RICHARDJ. BALDAUF,presiding DONALD C., University of Florida College of Medicine. 114. GOODMAN, Comparative studies on functional anatomy of the cerebellum. (15 min.) 9:20 115. HECHT,MAX,Queens College. The history of the frogs. (15 min.) 9:40 116. BAIRD,IRWINL., University of Kansas. Observations on the auditory apparatus in typhlopid snakes. (15 min.) 1O:OO 117. BAUMEL,JULIAN J., School of Medicine, Creighton University. The asymmetrical distribution of the posterior cerebral artery of the pigeon. (15 min.) T., University of Pittsburgh. The bird pterygoid, 10:20 118. JOLLIE,MALCOLM an example of functional modification. (15 min.) C., American Museum of Natural History. 10:40 119. MCKENNA,MALCOLM The shoulder girdle of the mammalian subclass Allotheria. (15 9:OO h.) 11:oo 120. DUBRUL,E. LLOYDAND DANIELM. LASKIN,University of Illinois. 11:20 Preadaptive potentiality of the mammalian skull. (15 min.) 121. EDINGER,TILLY, Harvard University. Behavioral specialization reflected in brain morphology. (10 min.) Demonstrations : 9 :00 A.M. to 12 :00 NOON Room F, Commodore Hotel (Note: this demonstration room will also be open Thursday afternoon from 1:OO to 6:OO P.M., Friday morning from 9:00 to 1 2 : O O NOON,and Friday afternoon from 1:00 to 4:OO P.M.) ALLENSPACH, ALLAN L. and HOWARDL. HAMILTON,Iowa State University. Mitotic patterns during occlusion and reopening of the esophagus in the chick. BALLWEG, ROBERTF. AND DANIELM. LILLY, St. John’s University, New York. Growth determinations in Paramecium caudatum by the formazan reaction. MAYNARD, EDITHA., University of Michigan. Cholinesterases in two autonomic ganglia of the lobster, Homarus amerieanus. RHODES,RONDELLH. AND H. CLARKDALTON,New York University. Histochemical patterns in developing pituitaries in two strains of Mexican axolotl, Siredon mexicanum. 318 AMERICAN SOCIETY O F ZOOLOGISTS THURSDAY AFTERNOON, DECEMBER 29 Symposium: Spennatozoan motility, 11. 2:00 P.M. Windsor Ballroom, Commodore Hotel KEITH R. PORTER,presiding 2 :00 126. D. W. FAWCETT, Harvard University. Ultrastructure in relation to sperm motility. Leeds University. Biophysical principles under2 :45 127. F. G.E.PAUTARD, lying sperm motility. 3:30 128. L. NELSON, Emory University. Physicochemical aspects of sperm motility. 4:15 Discussion. Symposium: Submicsoscopic c e h l a r structure and function. (Unsolved Problems in Biology, 1960) 2 :00 P.M. (No abstracts) Organized by Barry Commoner and Viktor Hamburger, Washington University. Co-sponsored by Sections F and G, AAAS and by The American Society of Zoologists. Grand Ballroom, Commodore Hotel BARRYCOMMONER, presiding 2 :00 129. SIEKEVITZ, PHILIP,Rockefeller Institute. Biochemical significance of the endoplasmic reticulum. (35 min.) ALBERTL., Johns Hopkins University. Chemical and 2 :40 130. LEHNINGER, enzymatic organization of mitochondria. (35 min.) 3 :20 131. SCHULTZ, JACK,Institute for Cancer Research. Genetic activity and chromosome structure. (35 min.) 4: 00 132. DAVISON,PETER F., Massachusetts Institute of Technology. Molecular organization in the neuron. (35 min. ) 4:35 Discussion. Session K: Comparative Endocrinology, 111. 2 :00 P.M. Windsor Terrace, Commodore Hotel JERRY J. KOLLROS, presiding H. E., Brown University. The initiation of 133. VAN HEYNINGEN, thyroid function in the mouse. (Introduced by J. Walter Wilson) (15 min.) FLORENCE, Washington University. Influence of thyroid 2:2O 134. MOOG, hormone on the functional differentiation of the duodenum in the chick embryo. (15 min.) PHILIPF., JR., A. c. BALLASAND D. W. SLINGERLAND, 2:40 135. MULVEY, Veterans Administration Hospital, Boston. The in vitro stimulation of thyroidal activity by propylthiouracil. (15 min.) 3:OO 136. FREGLY,MELVINJ., University of Florida College of Medicine. Spontaneous activity of hypothyroid rats in cold air. (15 &.) Smith College. The 3:20 137. CARPENTER,ESTHERAND ANN K. HOLMGREN, effect of excess vitamin A on the basal metabolism and on the histology of the thyroid and anterior pituitary glands of young female rats. (15 min.) 2:OO 319 LIST O F TITLES 3:40 4:OO 138. CORTELYOU, JOHNR., De Paul University. The effects of commercially prepared parathormone on calcium and phosphorus levels in unoperated Rana pipiens. (15 min.) 139. WELTMAN,A. STANLEY,ARTHUR M. SACKLERAND RICHARD ANDELMAN, Laboratories for Therapeutic Research, Research Institute of the Brooklyn College of Pharmacy. Effects of thymectomy on the blood cells and platelets of male rats. (15 min.) Session L: Animal Behavior and Sociobiology, IV. Sexual behavior and communication. 2 :00 P.M. (In collaboration with the Section on Animal Behavior and Sociobiology of The Ecological Society of America) Windsor Court, Commodore Hotel J. L. FULLER,presiding 2:OO 140. MCGILL,THOMAS E., Williams College. Sexual behavior in inbred strains of mice. (Motion picture, 15 min.) 2:20 141. MORGENSTERN, LARRYL., University of Kansas. Changes in 2:40 142. 3:OO 143. 3:20 144. 3:40 145. 4:OO 146. 4:20 147. sexual behavior in spayed female guinea pigs following anterior hypothalamic lesions. (Introduced by William C. Young) ( 15 min. ) MOORE, THOMAS E., University of Michigan. Acoustical behavior and courtship of conenose bugs (Hemiptera, Reduviidae, Triatominae). (Motion picture, 15 min.) (No abstract) SHAW,KENNETH C., University of Michigan. An experimental analysis of the singing behavior of the true Katydid (Pterophylla : Tettigoniidae). (15 min.) STOUT,JOHN F., University of Maryland. The significance of sound production during the reproductive behavior of Notropis analostanus. (15 min.) E. AND JOSEPHMARSHALL, University of MaryWINN, HOWARD land. Sound production of squirrelfishes. (15 min.) University of Texas and HUNTER,D. K. AND ROBERTSELANDER, American Museum of Natural History. Sound spectrographic analysis of a continuous singer, the mockingbird. (15 min.) HARTSHORNE, JAMESM., Cornell University. The role of learning in the development of the Eastern Bluebird's vocal repertoire. (15 min.) Organization Meeting : Division of Vertebrate Morphology. 1 :30 P.M. Parlors B and C, Commodore Hotel Session M : Vertebrate Morphology, II. 2 :30 P.M. Parlors B and C, Commodore Hotel HARVEYI. FISHER,presiding 2:30 148. FOWERS,KAREN S., W. S. TYLER,L. M. JULIAN AND P. W. GREGORY, University of California, Davis. Articulation of the lumbar vertebrae in brachycephalic bovine dwarfs. (15 min.) 320 AMERICAN SOCIETY O F ZOOLOGISTS 2:50 149. ERIKSON, G. E., Harvard Medical School. The vertebral column of New World primates. (15 min.) 3:10 150. HILDEBRAND, MILTON,University of California, Davis. Relative variability of body proportions in marsupial and other mammals. (10 min.) 3:25 151. BAKER-COHEN, K. FRANCE, New York Zoological Society. Situs inversus and vascular asymmetry in xiphophorin fishes. (15 min.) ROBERT C., University of Missouri School of Veterinary 3 :45 152. MCCLURE, Medicine. Occurrence of the zygomatic groove and canal in the sphenoid bone of the dog skull (Canis familiaris). (12 rnin.) W. AND A. P. LONG,Detroit Institute of Cancer Re4:02 153. PRYCHODKO, search and Wayne State University. Effect of isolation on the body weight of laboratory mice. (10 min.) 4:17 154. NATHAN, HENRYC., The Wellcome Research Laboratories, Tuckahoe 7,New York. The use of specific pathogen-free mice for tumor studies. (Introduced by Samuel Bieber) (15 min.) L. AND J. H. LEATHEM, College of St. Teresa 4:37 155. GROSSO,LEONARD and Rutgers University. Carcinogen-induced hepatic tumors in mice. (Introduced by A. F. Hopper) (10 min.) Business Meeting Section F, AAAS. 5:OO P.M. East Ballroom, Commodore Hotel Business Meeting The American Society of Zoologists. 5:30 P.M. East Ballroom, Commodore Hotel THURSDAY EVENING, DECEMBER 29 Zoologists’ Dinner 7:OO P.M. (Joint dinner for Section F, AAAS and The American Society of Zoologists) Vice Presidential Address, “AnEmbryologist Visits Japan” VIKTOR HAMBURGER West Ballroom, Commodore Hotel EMIL WITSCHI,presiding AAAS-Biologists’ Smoker. 9 :00 P.M. Joint smoker for Sections F and G, AAAS and The American Society of Zoologists West Ballroom and adjacent ballrooms, Commodore Hotel FRIDAY MORNING, DECEMBER 30 Symposium: Spermatozoan motility, 111. 9 :00 A.M. Windsor Ballroom, Commodore Hotel R. J. FLIPSE,presiding 9:00 156. C. TERNER, Boston University. Metabolic reactions in spermatozoa. 9:46 157. P. H. GONSE,Centre de Recherches de Lyon. Respiration and oxidative phosphorylation in relation to sperm motility. 321 LIST O F TITLES 10:30 158. G. W. SALISBURY, University of Illinois. Ionic and osmotic re11:15 quirements . Discussion. Symposium: Physiology of molluscs, I I . 9: 00 A.M. Grand Ballroom, Commodore Hotel RICHARDA. BOOLOOTIAN, presiding 9:OO 159. WELSH,JOHNH., Harvard University. Neurohormones in molluscs. (30 min.) 160. GALTSOFF, PAULS., U.S.Fish and Wildlife Service, Woods Hole. Physiology of reproduction in molluscs. (30 min.) 10:20 161. KOHN,ALAN J., Florida State University. Chemoreception in gastropods. (30 min. ) 11:OO 162. PICKENS,PETERE., Institute of Marine Science, University of Texas. Variations in the heart rate of mussels from different habitats. (Introduced by T. H. Bullock) (15 rnin.) 9:40 Symposium : Teaching animal behavior, I. Animal behavior in biology teaching. 9:00 A.M. (No abstracts) Organized by E. B. Hale, Pennsylvania State University for the Division of Animal Behavior and Sociobiology of The American Society of Zoologists in collaboration with the Section of Animal Behavior and Sociobiology of The Ecological Society of America. Co-sponsored by Section F, AAAS and The National Association of Biology Teachers. East Ballroom, Commodore Hotel E. B. HALE,presiding 163. HALE, E. B., Pennsylvania State University. Introduction to the symposium. 164. SCOTT,J. P., Jackson Memorial Laboratory. Animal behavior as a biological discipline. 165. GINSBURG, BENSON, E., University of Chicago. Animal behavior in college biology. 166. BAKER,ARTHURJ., Crystal Lake High School, Crystal Lake, Illinois. Animal behavior in secondary-school biology. Session N : Comparative Physiology, III. Physiology of arthropods. 9: 10 A.M. Windsor Terrace, Commodore Hotel T. H. WATERMAN, presiding 9: 10 167. BREBBIA, D. ROBERT,Fordham University. Electrocardiogram of the housefly, Musca domestica L. (Introduced by D. Ludwig) 9: 30 (15 min.) 168. DOANE,WINIFREDW., Yale University. Corpus datum-complex and ovarian transplantations in the mutant female sterile (2) adipose of Drosophila melanogaster. (Introduced by Sheila J. Counce) ( 15 min.) 322 AMERICAN SOCIETY OF ZOOLOGISTS E. S., L. B. BARTONBROWNE, L. F. DODSON AND J. K. 9:60 169. HODGSON, KIRALY,Columbia University, Commonwealth Scientific and Industrial Research Organization and National Biological Standards Laboratories, Australia. Pharmacological properties of roach corpus cardiacum. (15 min.) 1O:lO 170. HICHAR,JOSEPH K., Parsons College. Differential effect of picrotoxin on crustacean nerve cords. (15 rnin.) DONALD M., University of Michigan. Forms of activity 10:30 171. MAYNARD, within the neuropile of the spiny lobster. (15 min.) JAMESB. AND DONALD KENNEDY, State University Col10:60 172. PRESTON, lege of Medicine in Syracuse and Stanford University. Properties of spontaneously active units in the ventral nerve cord of the crayfish. (Introduced by William H. Telfer) (15 rnin.) 11:lO 173. KENNEDY, DONALD AND JAMESB. PRESTON, Stanford University and State University College of Medicine in Syracuse. Complex responses of central neurons in the crayfish to presynaptic and direct stimulation. (Introduced by Victor C. Twitty) (15 min.) 11:30 174. ECKERT, ROGERO., Columbia University. Role of stretch receptor system in crayfish swimming reflex. (Introduced by E. S . Hodgson) (15 min.) Session 0 : Developmental Biology, 111. 9 :00 A.M. Parlors B and C, Commodore Hotel MELVIN SPIEGEL,presiding CHARLES, CLYDE E. JOHNSON, ERWINGOLDBERGAND 175. NORMAN, I. D. PORTERFIELD, West Virginia University. A chemically defined maintenance medium for bovine sperm. (Introduced by Lloyd R. Gribble) (15 min.) 9:20 176. RULON,OLIN, Northwestern University. The extension of fertilizability and life in sand dollar eggs with cobalt, cysteine and thioglycolic acid. ( 15 min.) MARIADE ISSEKUTZ AND ALEXANDERWOLSKY, Manhat9:40 177. WOLSKY, tanville College and Fordham University. The effect of a carcinostatic antimetabolite on the development of sea urchin eggs. (15 min.) University of Cali1O:OO 178. SMITH,ARLANE. S. AND A. M. SCHECHTMAN, fornia, Los Angeles. Protein changes during early amphibian development. ( 15 min.) 10:20 179. MUCHMORE,WILLIAMB., University of Rochester. Muscle proteins in early amphibian embryos. (15 min.) 10:40 180. BLACK,ROBERTE., College of William and Mary. Krebs-cycle dehydrogenases, DPNH-oxidase and cytochrome oxidase in homogenates of developing oyster-eggs. (15 min.) 11:OO 181. ESTES,ZANEE., Yale University. Cytochrome oxidase activity of intact and digitonin-treated chick liver mitochondria during development. (Introduced by E. J. Boell) (15 min.) 11:20 182. BERG, GEORGEG. AND J. SZEKERCZES, University of Rochester. Trimetaphosphatase in the yolk sac of vertebrates. (15 min.) 11:40 183. ENDERS, ALLEN C., Rice University. Studies on the blastocyst of the nine-banded armadillo during the period of delayed implantation. (15 min.) 9:OO LIST OF TITLES FRIDAY AFTERNOON, DECEMBER 30 Symposium: Spermatozoan motility, N. 2 :00 P.M. Windsor Ballroom, Commodore Hotel TERUHAYASHI, presiding 184. J. TIBBS,University of St. Andrews. ATP-ase and acetylcholinesterase in relation to sperm motility. 2:45 185. D. W.BISHOP,Carnegie Institution of Washington. Reactivation of extracted sperm-cell models in relation to the mechanism of motility. 3:30 186. C. J. BROKAW, University of Minnesota. Studies on isolated flagella. 4: 15 Discussion. 2:OO Symposium : Teaching animal behavior, I I . Techniques in teaching animal behavior. 2:OO P.M. (No abstracts) (Panel and open discussion) East Ballroom, Commodore Hotel ARTHUR J. BAKER,presiding 187. CARPENTER, C. R.,Pennsylvania State University. Film instruction. 188. DILGER,WILLIAMC., Cornell University. Vertebrate materials. 189. SMYTH,THOMAS, JR., Pennsylvania State University. Invertebrate materials. 190. GOHMAN,WALTER, Iowa State Teachers College Laboratory School. Special projects. Open discussion Session P : Invertebrate Zoology, Parasitology and Protozoology. 2 :00 P.M. Windsor Court, Commodore Hotel RICHARDP. HALL,presiding 2:OO 191. MURCHIE,WILLIAMR., The University of Michigan Flint College. Production of spermatophores by Dendrobaena samarigera Rosa 1893. (12 rnin.) DOMINICAND EUGENE BIEGELMAN, Wayne State Uni2:17 192. DEGIUSTI, versity. The pH of the gut of the amphipods Hyalella azteca and Gummarus sp. (12 min.) JOHNC., Cornell University. The nature of the con2:34 193. FERGUSON, nective tissue of the body wall, retractor harness and cardiac stomach of the starfish, Asterias forbesi. (Introduced by J. M. Anderson) (10 min.) 2:49 194. OGREN,ROBERTE.,Dickinson College. Observations on the immature hexacanth embryo of Hymenolepis diminuta, a tapeworm of mammals. (10 min.) 3:04 195. WEISSENBERG, J. RICHARD,Emeritus Professor, 5225 Schuyler Street, Philadelphia 44, Pa. Further studies on the intracellular microorganism observed in the lymphocystis disease of fish. (15 min . ) 323 324 AMERICAN SOCIETY OF ZOOLOGISTS 3:24 196. FEDER,WILLIAMA., Agricultural Research Service, U.S. Department of Agriculture, Orlando, Florida. Osmotic destruction of plant parasitic and saprophytic nematodes by the addition of sugars to soil. (10 min.) 3:39 197. FINLEY,HAROLD E., Howard University. Pseudo-mating of Spirostomum. (15 min.) 3:59 198. SIEGEL,R. W. AND L. LARISON,University of California, Los Angeles. Induced illegitimate mating in Paramecium bursaria. (15 rnin.) 4:19 199. WICHTERMAN, RALPH,Temple University. Survival and reproductive ability after x-irradiation in four species of Paramecium. (15 min.) 4:39 200. SATO,HIDEMI,Dartmouth Medical School. A morphological study on the mitochondria of Tetrahymena geleii W. (15 min.) 4: 59 201. LEVINE,LAURENCE, Wayne State University. Visualization of sulfhydryl groups in Vorticella convallaria. (15 min.) Session Q: Comparative Physiology, IV. Physiology of arthropods. 2: 00 P.M. Windsor Terrace, Commodore Hotel J. H. WELSH,presiding 202. WINSTON, PAULW., University of Colorado. A possible humidity receptor mechanism in the clover mite, Bryobia praetiosa Koch. (10 min.) AND MERLE S . BRUNO, Stanford University and DONALD 2:15 203. KENNEDY, Harvard University. On the spectral sensitivity of visual systems in decapod crustacea. (15 min.) 2:35 204. SKINNER, DOROTHY M., Yale University. Protein synthesis in the Cecropia silkmoth. (Introduced by D. E. Bliss) (15 min.) R. E. AND JACK COLVARDJONES,University of Mary2:55 205. WHEELER, land. The mechanics of copulation in Aedes aegypti (L). mosquitoes. (10 min.) 3:10 206. MILKMAN,ROGER,Syracuse University. Rapid temperature adaptation in Drosophila melanogaster pupae. (15 min.) 2:OO Session R: Genetics and Cytology. 2: QO P.M. Parlors B and C, Commodore Hotel presiding DONALD F. POULSON, P. w., w . s. TYLERAND L. M. JULIAN,University of 207. GREGORY, California, Davis. Evidence that the Dexter mutant is genetically related to recessive achondroplasia. (15 min.) 2:20 208. TYLER,w. s., L. M. JULIANAND P. w. GREGORY,University of California, Davis. Standard values of metacarpal indices for achondroplastic brachycephalic dwarfs and controls. ( 15 min.) H. A. AND M. M. GREEN,University of Notre Dame and 2:40 209. BENDER, University of California, Berkeley. Effects of a suppressor of the 1234kallele in Drosophila melanogaster. (Introduced by R. E. Gordon) (15 min.) 3:OO 210. RIZKI, M. T. M., Reed College. The nature of the autofluorescence of the fat cells of Drosophila. (15 min.) 2:00 325 LIST O F TITLES 211. KING, R. C., Northwestern University. The hereditary ovarian tumors of the f e s mutant of Drosophila melanogaster. (15 min.) 3:40 212. MERRIAM, R. W., Columbia University. Structural variations and composition of the nuclear envelope. (15 min.) 4:OO 213. KAYE, JEROME S., University of Rochester. Acrosome differentiation in the cricket. (15 min.) 4:20 214. NICKLAS, R. BRUCE,Yale University. The cytology of Mycophila speyeri and the origin of the gall-midge chromosome cycle. (15 min. ) 4:40 215. WORLEY, LEONARD G. AND BETTYHERSHENOV, Brooklyn College. Electron microscopy of the elaboration of protein yolk by the Golgi complex during the early development of Crepidula. (15 min.) 5:OO 216. PENNEY, DAVIDP., W. C. DIXONAND D. I. PATT,Boston University. The cytology of adrenocortical regeneration in selected sites in the rat. (15 min.) 3:20 Session S: Experimental Biology. 2: 00 P.M. West Ballroom, Commodore Hotel DANIELLUDWIG, presiding 2:OO 217. EVENSTEIN,DOROTHY,GEORGEH. FRIED,SOPHIE JAKOWSKA, SAMUELKOOPERSTEIN AND WILLIAMANTOPOL,Levy Foundation Laboratories, Beth Israel Hospital and Medical Department, Port of New York Authority. Effects of injected nutrient supplements on weights, oxygen consumptions and respiratory enzyme levels of fasted salamanders. (15 min.) PAULK., Brown University. Histological observations on 2:20 218. NAKANE, the effect of intraperitoneally injected Thorotrast on the surface of the mouse liver. (Introduced by E. H. Leduc) (15 min.) 2:40 219. CHENEY,RALPHHOLTAND CARLCASKEYSPEIDEL,Brooklyn College and University of Virginia. Differential effects of ultraviolet and x-ray gamete irradiation in the sea urchin, Arbacia. (Motion picture, 15 min.) 3:OO 220. ALLEN, ROBERTD., Princeton University. Streaming in cytoplasm dissociated from the giant ameba, Chaos chaos. (Motion picture, 15 min.) AND HARRY A. CHARIP3:20 221. ANTOPOL,WILLIAM,ALFREDPERLMUTTER PER, Beth Israel Hospital and New York University. The inoculation of eggs by sperm previously treated with virus. (15 min.) 3:40 222. COSGROVE,WILLIAM B. AND MIKE MCSWAIN, University of Georgia. Absence of the kinetoplast in trypanosomids of insects. (10 min.) AND GEORGECALVOSA, 3:55 223, WINKERT,JOHNW., ALBERT S. GORDON New York University. Chromatographic separation of human urinary erythropoietic stimulating factor (ESF). ( 15 min.) 4:15 224. CROSS,J. C., Texas Technological College. A virus-like substance produced in v i m . ( 15 min.) ROBERT F. AND ARTHUR B. CALLAHAN, Boston Univer4:35 225. SLECHTA, sity. Blood pressure and flow characteristics in the microcirculation of the hamster cheek pouch with sodium pentobarbital anesthesia. (10 min.) 326 AMERICAN SOCIETY O F ZOOLOGISTS PAPERS READ BY TITLE Papers read by title have been arranged alphabetically by the name of the first author. 226. ALLEN, M. JEAN, Wilson College. Cytochemical observations on the developing oocytes and attached nurse cells of the polychaete, Diopatra cuprea. 227. ALLEN, M. JEAN,Wilson College. Histochemical observations on the early developmental stages of the polychaete, Chaetopterus pergamentaceus. AND JERRYJ. KOLLROS,State University of Iowa. 228. ANDERSON,EVERETT The ultrastructure and development of the basement membrane of balancers in Ambystoma embryos. 229. ANDRUS,WILLIAMD. AND A. C. GIESE,Stanford University. Regulation of sodium and potassium in the ciliate, Tetrahymena pyrifomnis strain W . 230. ANGELONE,LUIS,Washington University. Effect of the thyroid and adrenals on rat erythrocyte glycolysis. LIEBERMAN, University of Massachusetts. 231. BARTLETT,L. M. AND EDWARD Possible visual imitation in Coturnix quail. 232. BATTLE,HELENI. AND HANSW. LAALE,University of Western Ontario. Trypan blue-induced anomalies in embryos of the zebrafish (Brachydanio rerio). TIBBITTS,University of Illinois and 233. BIRGE, WESLEYJ. AND F. DONALD University of Nevada. The use of sodium chloride in minimizing tissue distortion resulting from fixation by chemical means. 234. BOYD,ELIZABETH M. AND DOROTHY COVALT DUNNING,Mount Holyoke College. Metazoan parasites of the short-tailed shrew, Marina brevicauda Say in Western Massachusetts. 235. CHAET,ALFRED B., R. SELLERSAND D. KENNAN,American University. Further characteristics of a burn toxin(s) from the starfish, Asterias forbesi. SEARSAND MAURICE HARTMAN, Indiana University. Reorgani236. CROWELL, zation capacities of dissociated tissues of Campanularia flexuosa. 237. DEWITT,ROBERTM., University of Florida. Glycogen levels in fresh and starved Uniomerus obesus, a freshwater bivalve. 238. DOUGHERTY, ELLSWORTH C., B J ~ R NSOLBERG AND D. JOANNE FERRAL, Laboratory for Gnotobiotic Studies, Berkeley, California. Axenic cultivation of a rotifer species. 239. EAKIN, RICHARD M., University of California, Berkeley. Number of photoreceptors and melanocytes in the third eye of the lizard, Sceloporus occidentalis. 240. FILOSA, M., Johns Hopkins University. The effects of ethionine on the morphogenesis of cellular slime molds. 241. GREENBERG,SYLVIAS. AND M. J. KOPAC,Genetics Laboratory, New York Zoological Society and New York University. Melanogenic enzyme activity in xiphophorin fishes. 242. GREENWALD, GILBERT S . , University of Washington. Gonadotrophic content of the pituitary of the lactating mouse. 243. GREENWALD,GILBERTS . , University of Washington. The antifertility effects in pregnant rats of a single injection of estradiol cyclopentylpropion ate. LIST OF TITLES 244. 245. 246. 247. 248. 249. 250. 251. 252. 253. 254. 255. 256. 257. 258. 259. 260. 261. 262. 263. GROSSO, LEONARD L., College of Saint Teresa. The effect of testosterone propionate on the weight and 0-glucuronidase level of the ventral prostate and seminal vesicle of the castrate immature Wistar rat under different dietary regimes. HALL,R. P., New York University. Duration of sulfonamide resistance and its reversibility in Chilomonas. HANSBOROUGH, LOUIS A. AND LOWELLE. DAVIS, Howard University. Differentiation of the eye primordium of the mouse in the chick embryo. HANSBOROUGH, LOUISA. AND GLORIAJ. WILLIAMS,Howard University. Regulation in the developing wing of the chick embryo. I. Differentiation of grafted somites. W. AND SUSANKNOVACS,Mount Union College and HINSCH,GERTRUDE Mount Holyoke College. Alkaline phosphatase in the trachea and esophagus of the developing chick. UPLAN,HAROLD M., Southern Illinois University. Electrophoretic analysis of protein changes during growth of Pseudemys turtles. KATSH,SEYMOUR, University of Colorado Medical Center. Mediation of immunologically-induced aspermatogenesis by a nonacid-fast bacterium. KISCHER, C. WARDAND HOWARD L. HAMILTON, Iowa State University. Effects of respiratory inhibitors on the development of the down feather. KOHN,ALAN J., Florida State University. Development in marine gastropod molluscs of the genus Conus and its ecological significance. KRAMER, SOLAND HELMUTMUELLER,State University of New York and Cambridge University, England. Band pattern changes in insect muscles during stretch and contraction. J. V. AND J. H. MCALEAR,Albany Medical College, Veterans LANDAU, Administration Hospital and New York State Department of Health, Albany. The ultrastructure of primary and FL-amnion cells following exposure to high hydrostatic pressure. LATIMER, HOMERB. AND PAULB. SAWIN,University of Kansas and Jackson Memorial Laboratory. Variation in shape and position of some of the viscera in the rabbit. LIBBY,ERNESTL. AND PERRYW. GILBERT,Marineland Research Laboratory and Cornell University. Reproduction in the clear-nosed skate, Raja eglanteria. LYNN,GARDNER W. AND HENRYE. WACHOWSKI, Catholic University of America. Histological study of the thyroid and pituitary in the minnow Gambusia after exposure to high temperature and treatment with thiourea. MCFARLAND, L. Z., University of California, Davis. Salt excretion from the nasal glands from various species of the Pelicaniformes. L. Z., University of California, Davis. Salt excretion from MCFARLAND, the nasal glands of captive penguins. MCFARLAND, L. Z. AND M. T. CLEGG,University of California, Davis. Sexual behavior in r a m s and the effects of hypothalamic lesions. MAGRUDER, SAMUELR., Tufts University School of Medicine. Innervation of the tongue musculature of Eptesicus fuscus. MARGOLENA, LUBOWA., Animal Husbandry Division, Agricultural Research Service, United States Department of Agriculture. Season and comparative activity of wool follicles. MATEYKO, G. M. AND M. J. KOPAC,New York University. Cytological studies on renal cultures of Rana pipiens. 327 328 AMERICAN SOCIETY O F ZOOLOGISTS 264. 265. 266. 267. 268. 269. 270. DEN~FLE, Facult6 des Sciences, MAY,RAOULMICHEL AND JEAN-PIERRE University of Paris. Comparison of the direct action of ultra-violet and x-rays on the in vitro growth of nerve fibers from irradiated spinal cords of chick embryos. MONROY, ALBERTOAND M. LETIZIAVITTORELLI, University of Palermo, Italy. A study of the cell fluid proteins of the egg and developmental stages of Paracentrotus lividus. MOULTON, JAMES M., Bowdoin College. The acoustical anatomy of teleost fishes. RIZKI, M. T. M., Reed College. Intercellular effects of glucosaminehydrochloride on tumor formation in Drosophila melanogaster. ROCKSTEIN, M. AND R. SPRITZER, New York University School of Medicine and Marine Biological Laboratory. Light orientation in the starfish, Asterias forbesi. RUBEN,LAURENSN., Reed College. Further studies on implant-induced supernumerary limbs in urodeles. RUGGIERO, FRANKT. AND WALTERS. TYLER,University of California, Davis. Width of the proximal tibial epiphyseal lines from achondroplastic and control rabbits. RUGH, ROBERTSAND ERICAGRUPP,Columbia University. Congenital effects following low level x-irradiation. VANKIN,G . LAWRENCE AND H. CLARK DALTON, New York University. Analysis of tail darkening in hypophysectomized urodele larvae. VELARDO,JOSEPH THOMAS, Yale University. Response of the uterus of the rat to estradiol-l7@after different periods of time after ovariectomy. WEINTRAUB, ARTHUR H., JOHN w. WINKERT AND ALBERTs. GORDON, New York University. Effects of acute hemorrhagic anemia and erythropoietin on the mitotic activity of nucleated red cells of rat femoral bone marrow. WESSELLS, NORMAN K., Yale University. Initiation by thyroxine of chick epidermal differentiation in protein-free chemically defined nutrient media in vitro. WILBER,CHARLESG. AND FREDERICK N. SUDAK,Loyola College and Albert Einstein College of Medicine. Circulatory responses of Elasmobranchs to hemorrhage. I 271. 272. 273. 274. 275. 276. Abstracts Abstracts are arranged in a single sequence alphabetically according to the last name of the first author. Papers 226 to 276 are read by title. The number of an abstract will give a clue to its location in the program. An author index follows the abstracts. 85 KENNETH ALLEN, University of California, Los Angeles. Nitrogen metabolism in the mollusca. (30 min.) Nitrogen metabolism in molluscs has for the most part centered around nitrogen catabolism, and the illucidation of enzymes involved in the digestion of proteins. Metabolic pathways for protein synthesis are lacking for molluscs, but several enzyme systems involved in protein intermediary metabolism have been reported. The enzymes that have been studied are: amino acid oxidase, amine oxidase and transaminase. Recent studies on the amino acid constituents of molluscan tissue have implicated these compounds in osmoregulation. Amino acids have also been reported from molluscan shells, and biochemical studies on the protein of shell, conchiolin, have given information concerning its structure and terminal amino acids. Closely associated with the studies on amino acids, have been investigations involved with the phosphagen, arginine phosphate, and its metabolism. 226 M. JEAN ALLEN, Wilson College. Cytochemical observations on the developing oocytes and attached nurse cells of the polychaete, Diopatru cuprea. Cytochemical tests were performed on both whole mounts and serial sections. It was reported earlier (Allen, Anat. Rec., 1957) that RNA is distributed in a n animal-vegetal gradient in fullygrown unfertilized eggs. Tests for RNA are strongly positive in the cytoplasm and nucleolus of both the unripe eggs and the two strings of algal-like nurse cells attached to them. The writer recently has demonstrated two narrow cytoplasmic bridges, each traversing the transparent cell membranes of the proximal nurse cell and egg. There is an apparent continuity of cytoplasmic material, strongly positive for RNA, from the proximal nurse cells through the cytoplasmic bridge to the developing oocyte. These bridges also have been demonstrated following lipid staining in whole mounts where they appear as clear or finely granular areas, occasionally with small lipid (probably phospholipid) droplets. The yolky cytoplasm of the oocyte appears packed with lipid droplets of various sizes, and small lipid granules occur in a dense polar cap between the animal pole and germinal vesicle. Lipid granules and occasional droplets appear in the attached nurse cells. In oocytes, areas comparable to those containing the small lipid granules were shown also to reduce Nitro-BT, possibly reflecting mitochondria1 activity. Glycogen tests demonstrate occasional positive granules in fully grown oocytes and a few granules in the nurse cells of developing oocytes. Tests for alkaline phosphatase were negative for both oocytes and nurse cells. (Living material was collected a t the Woods Hole Marine Biological Laboratory.) (Supported by grant 6-8775 from N.S.F.) 227 M. JEAN ALLEN, Wilson College. Histochemical observations on the early developmental stages of the polychaete, Chaetopterus pergamentaceus. Unfertilized eggs and cleavage blastomeres of Chaetopterus have perinuclear rings of RNA. The remaining cytoplasmic RNA appears as a diffuse network surrounding the endoplasmic spherules. The migration of endoplasmic spherules a t maturation results in an animal-vegetal gradient of RNA with the residual substance of the germinal vesicle staining intensely. Late cleavage and early swimming larvae have a periphero-central gradient of RNA, a consequence of the central concentration of endoplasmic spherules lacking RNA. The unfertilized egg appears packed with glycogen granules diffusely distributed throughout the endoplasm. During maturation and early cleavage the outer endoplasm is negative for glycogen, but the residual substance and remaining endoplasm stain intensely. The endoplasm of later cleavage stages and blastulae is strongly positive, particularly the innermost portions of mid-cleavage blastomeres. In early swimming larvae and 26-hour trochophores most cells contain glycogen while in 21h-day trochophores most of the glycogen has disappeared. The fertilization membrane contains a polysaccharide which is not glycogen (or possibly a muco- or glycoprotein), as do the “pellicle,” oral lining, and large intensely staining cells around the mouth of 2%-day trochophores. Lipid spherules are distributed diffusely throughout the endoplasm of unfertilized eggs but with the migration of the endoplasmic spherules a t fertilization become distributed in a vegetalanimal gradient. The endoplasm of early cleavage blastomeres appears packed with lipid spherules. During later cleavage and blastula formation there i s a progressive concentration of lipids in the potential endodermal cells. In 26hour trochophores lipids are concentrated primarily in the basal ends of the endoderm cells. Alkaline phosphatase tests are negative for all stages tested through 7-day trochophores. (Embryological stages were obtained at the Duke University Marine Laboratory and the Woods Hole Marine Biological Laboratory). (Supported by grant 6 8 7 7 5 from N.S.F. and a summer grant from Wilson College.) 329 330 AMERICAN SOCIETY O F ZOOLOGISTS 220 ROBERT D. ALLEN, Princeton University. Streaming in cytoplasm dissociated from the giant ameba, Chaos chaos. (Motion picture, 15 mk.) Cytoplasmic streaming associated with ameboid movement has traditionally been considered a property of intact cells. A short film will demonstrate the ability of ameba cytoplasm which has been dissociated from intact cells but not physically disrupted to stream for periods up to an hour at velocities often exceeding those in the intact cell, Dissociated cytoplasm is obtained by shattering the ends of quartz capillaries containing amebae under a pool of oil. While the pattern of streaming is often that of a fountain, as i n the intact cell, it is more frequently organized into U-shaped “units of streaming” i n which cytoplasm streams along one arm of the U toward the bend at a velocity 1% to 3 times that at which it moves away from the bend on the other arm of the U. This velocity difference was the intial clue leading to the discovery that the motive force for the streaming in both the U- and fountain-paUerns of streaming is a contraction of the cytoplasm as it changes direction at the front of the cell as proposed in the Fountain-Zone Contraction Theory of ameboid movement (Allen, 1960), further evidence for which w i l l be presented. (Supported by grant C-3022 from the U.S.P.H.S.) 122 ALLAN L. ALLENSPACH and HOWARD L. HAMILTON, Iowa State University. Mitotic patterns during occlusion and reopening of the esophagus in the chick. Colchicine solutions (0.002 mg i n 0.2 ml saline) were injected into the amniotic cavities of chick embryos at stages 26-31. Mitotic counts were made 2%-12 hours later on sections of the esophagus stained with iron-hematoxylin. During closure, the epithelial roof collapsed towards the floor in the region of the tracheal bifurcation, with no apparent increase in mitoses at the roof-floor juncture. The mitoses were widely scattered ahead and behind the point of fusion, and occurred mainly near the basement membrane. In the occluded zone, there were very few dividing cells; these occurred in the lateral edges of the broad anterior portion, and near the basement membrane of the more posterior cylindrical esophageal cord. With the appearance of vesicles, there was an abrupt increase in mitotic rate. Dividing cells were almost always next to cavities. This is considered a secondary phenomenon, due to the withdrawal of cells to their attachment site when rounding up for division, rather than a primary cause of vesiculation, because some vesicles occurred without mitoses surrounding them. Likewise, in the completely reopened esophagus with single lumen, divisions were adjacent to the cavity as in the neural tube. It appears that closure of the normal esophagus is accompanied by a change from a sharply-deh e d inner limiting membrane to an irregular boundary which shows protrusions of short proto- plasmic processes between roof and floor. Reopening occurs by cellular separation and possibly degeneration. Mitotic activity does not seem to be directly involved in either process. (Sup ported by grant RG-3813 (C7) from the U.S.P.H.S.) 228 EVERETT ANDERSON and JERRY J. KOLLROS, State University of Iowa. The ultrastructure and development of the basement membrane of balancers in Ambystoma embryos. Balancers were obtained from Ambystoma opacum and A. jeflersonianum embryos in stages 34-45. The epithelium covering the balancer consists of two layers of cells. Beneath the basal layer of cells at stage 34 is the relatively thin basement membrane. In subsequent stages (3840) a progressive increase in thickness and staining capacity of the basement membrane is observed. Electron micrographs of the basal epithelial cells at stage 34 reveal large pseudopodial extensions originating from their basal parts. Most of the cytoplasmic organelles, e.g., mitochondria and endopIasmic reticulum, are found aggregated just above the extensions. Vesicular elements of the endoplasmic reticulum are often found within the extensions. The surfaces of many extensions are free of formed elements; however, a few fine filaments, randomly oriented, are located at the periphery, in close contact with the limiting plasma membrane. In stages 36-45 no basal extensions are seen; the basement membrane has increased i n thickness, being constituted mainly of many fine randomly oriented filaments. (Supported by grants RG-4706, 5749 and A-2202 from the U.S.P.H.S.) 229 WILLIAM D. ANDRUS and A. C.GIESE,Stanford University. Regulation of sodium and potassium in the ciliate, Tehahymenu p y r i f o n i s strain W. Although some protozoa are able to withstand great changes in environmental salt content and a true ionic regulation by them is to be expected, ionic regulation has been little studied in ciliates. For such a study Tetrahymena, grown axenically in media similar in sodium content to 5, 10 and 30% sea water, were employed. Relative to cell total nitrogen or packed volume, cells from all three media accumulate potassium and extrude sodium. Cells from 10% medium show similar gradients on a dry weight basis. Total nitrogen was the usual basis of comparison. Physical and chemical agents altering cell metabolism were employed to investigate the origin of such gradients. In cells from three media, the established gradients are lost at 6”C, but regained at 25°C. Potassium reaccumulation shows a QIO of 3 in “10%” cells. In “10%” cells the reversible loss produced by anoxia of 1h the cell potassium, is not accompanied by net sodium movement. At room temperature monoiodoacetic acid (I-AcA), 2,4-dinitrophenol (DPN) and sodium azide produce partial loss of potassium without concomitant sodium gain. Cells in I-AcA and DNP demonstrate the usual cold-induced movements, though potassium is reaccumulated to an 331 ABSTRACTS intermediate level. Ouabain at 1 X M does not cause potassium loss or sodium gain. In Tetrahymena two mobile fractions of cell potassium seem related to metabolism, while the connection between cell sodium and metabolism remains unclear. (Supported in part by grants C-3461(Cl) and HF-10,203 from the U.S.P.H.S.) 230 LUIS ANGELONE, Washington University. Effect of the thyroid and adrenals on rat erythrocyte glycolysis. The response of the oxidative metabolism of human (Angelone et al., '54) and rat (Barker, '52) erythrocytes to thyroid hormone as well as rat erythrocytes to adrenal cortical hormones (Angerer et al., '47), and the fact that mature erythrocytes are 90-95% dependent upon anaerobic glycolysis for their energy suggested hormonal effects might be illustrated by measuring the glucose utilization after exposure to various hormone levels. Thyroid or adrenal insufficiency was produced in rats by surgically removing the thyroids or adrenals, respectively. Thyroxine or triiodothyronine was given to rats in their drinking water postoperatively for 14 to 24 days; or cortisone given subcutaneously for 5 days (1 mg/day). Heparinized blood was placed into a water bath (37.5'C), shaken gently, and samples withdrawn at intervals for glucose analysis (Nelson-Somogyimethod). The pg of glucose utilized/ hour/billion red cells was calculated from the cell count and hematocrit. A comparison to normal resulted in the following: Thyroparathyroidectomized (Tx) = -23%, Tx plus thyroxine 25%, Tx plus triiodowater (250 pg % ) = 17%, normal thyronine water (100 pg% ) = plus thyroxine water (250 pg% ) = - 42%, adrenalectomized (Adx) plus tap water = - 12%, 9 % , Adx Adx plus salt water (1% NaCl) = plus cortisone = 0 % , normal plus cortisone = -46%. The data indicate that the glucose metabolism of these cells may be strongly influenced by the thyroid and adrenal hormones, and further, that the effects do not parallel other tissues. No explanation for this is apparent at the present time. (Supported by grant RG-4980 from the U.S.P.H.S.) hatchability and more abnormalities and led to the present experiments. During 1959-60, influenza A' virus was introduced by the above method into eggs of brook trout, Salvelinus fontinalis, rainbow trout, and striped killash, Fundulus majalis. Prolongation of standing time of virus-sperm mixture before fertilization produced a decrease in number of fertilized eggs and increase of abnormal embryos. Brook trout eggs fertilized with virus-treated sperm and left in the dark showed retarded embryological development and higher mortality as compared with eggs fertilized with untreated sperm under similar conditions. However, striped killifish eggs fertilized with virus-treated sperm and raised in light showed accelerated embryological development and lower mortality. Besides introducing virus into eggs of fish and other species, this technique may also be used as a tool for the study of effects of nutrients, toxic materials, metabolites and antimetabolites, or immunologic reactions or immune tolerance. Experiments along these lines are now in progress. (Aided by The Joseph and Helen Yeamans Levy Foundation and grant H-2670, National Institutes of Health, U.S.P.H.S.) 46 THOMAS S. ARGYRIS and BERTIE F. ARGYRIS, Syracuse University. The differential response of epidermis and hair follicles to subcutaneously transplanted Ehrlich ascites tumor. (15 min.) Approximately two weeks after the subcutaneous inoculation of mice with Ehrlich ascites tumor, the tumor penetrates the subcutis or fatty layer of the skin. At this time the overlying epidermis shows marked enlargement due largely to basal cell hypertrophy and hyperplasia. The resting hair follicles however, do not show any stimulation even though they are much closer to the invading tumor than the epidermis. As the tumor continues its advance it penetrates the dermis and soon completely fills it. Throughout this time epidermal stimulation persists. The hair follicles on the other hand, continue to be unaffected even though they become completely surrounded by the tumor. When the advancing edge of the tumor comes to lie underneath the epidermis, stimulation of the epidermis markedly 221 diminishes. Further tumor growth results in WILLIAM ANTOPOL, ALFRED PERLMUTTER epidermal and hair follicle atrophy and degenand HARRY A. CHARIPPER, Beth Israel Hospi- eration. tal and New York University. The inoculation The results suggest that subcutaneously transof eggs by sperm previously treated with virus. planted Ehrlich ascites tumor can invade mouse (15 min.) skin and result i n epidermal stimulation. MoreThe chicken egg shortage during World War over, the distance between tumor and overlying I1 necessitated a substitute for culturing viruses. epidermis is critical for epidermal stimulation to Hypodermic inoculation of virus into rainbow occur. The resting hair follicles however, are trout, Salmo gairdnerii, eggs was unsatisfactory. unaffected, even though the tumor eventually The egg contents escaped through the puncture surrounds them. This is of particular interest since it has been shown that the basal cells of wound. Subsequently virus and sperm were mixed before fertilization, so that virus might have the the epidermis and the cells of the resting hair opportunity to adhere to sperm and thereby be follicle have the same developmental capacity. introduced into the egg during penetration. Ex- Thus the physiological state of an epithelium can periments conducted in 194344 indicated that profoundly affect its response to growth-promoting influence from tumors. (Supported by grants this could be valid for Richettsia (murine typhus from the U.S.P.H.S., N.S.F. and American Cancer virus, Wilmington strain). Eggs fertilized by Society.) sperm mixed with this virus showed greater + + + 332 AMERICAN SOCIETY OF ZOOLOGISTS 71 LESTER R. ARONSON and RONALD HERBERMAN, Department of Animal Behavior, American Museum of Natural History. Persistence of a conditioned response in the cichlid fish, Tilapia macrocephala after forebrain and cerebellar ablations. (15 min.) Using an operant conditioning apparatus designed by Bitterman, male Tilapia were rewarded automatically with food for striking at a small plexiglass target placed i n the tank. A test consisted of 10 trials spaced at intervals of one minute or more. Latency, the interval between introduction of target and operant response, was measured i n seconds. After subjects were conditioned to criterion, three intact controls, 6 sham operates (cranium opened) and 4 subjects with both olfactory bulbs removed, continued responding with an average latency of “1” and with practically no variation except directly after operation. Three males with forebrains completely removed continued to respond but the average latency and variability i n latency increased considerably. Latency decreased temporarily in average and variability immediately following several days of n o testing or feeding. Two other males with forebrains ablated also exhibited increases in latency but ceased responding after the 7th and 8th trials. After ablation of the corpus cerebelli, 4 subjects continued responding with somewhat higher latencies than after forebrain ablation. Following removal of both forebrain and corpus cerebelli in two subjects, the latencies became even higher. These gradually decreased almost to the level of forebrain operates. Two males were conditioned to respond several months after forebrain ablation. No locomotory or other quaIitative differences in behavior of the operates were observed. The results support hypotheses discussed elsewhere that a basic function of the forebrain i n fishes is facilitation of responses organized in lower centers. Also suggested is the possibility that the cerebellum may have a comparable energizing action on motor processes. (R.H.: American Museum Undergraduate Research Participant supported in part by N.S.F.) 116 IRWIN L. BAIRD, University of Kansas. Observations on the auditory apparatus in typhlopid snakes. (15 min.) Study of prepared skulls and serially-sectioned heads indicates that the anatomy of the auditory apparatus in several species of typhlopid snakes differs considerably from that found i n most other ophidian families. In a l l species examined, the circumfenestral crest, a bony elevation elaborated by the prootic and opisthotic and surrounding the fenestra ovalis, is highly developed. Except i n T y p h l o p s punctatus, the crest almost completely encloses the juxtastapedial fossa and closely surrounds the shaft of the columella auris. As a result, the usual ophidian counterpart of a secondary tympanic membrane is eliminated (or greatly reduced), and the footplate of the columella auris and the terminal part of the periotic labyrinth (juxtastapedial sinus) occupy positions which may properly be considered to be intracapsular. Reconstructions of the saccule and cochlear duct show that these parts have certain characteristics reminiscent of those i n saurians, but other features of these parts and those of the periotic labyrinth are typically ophidian. It is tentatively concluded that the auditory apparatus i n typhlopids could have been derived only from primitive but definitive ophidian structures, and that the specializations noted represent adaptations to a burrowing habit. 51 WILLIAM K. BAKER, University of Chicago. Genetic control over the somatic differentiation of eye pigments in Drosophila. (15 min.) The genetic phenomenon of position effect may produce somatic tissue is which cells i n one portion of the tissue are producing one phenotype while identical cells i n another part have a different phenotype. By altering in various ways the genotype of the individual showing the somatic variegation and/or by altering the genotype of its parents, one can control the relative amounts of the two types of tissue. This phenomenon has been studied by using a position effect at the white locus of D. melanogaster that evokes p i g ment formation i n certain ommatidia of the compound eyes; other ommatidia do not differentiate pigment. The patterns of the pigmented and nonpigmented areas so produced follow quite closely the known cell lineage. Chromatographic analysis of these variegated eyes reveals that the red pigments and their pteridine precursors are present in different relative concentrations than observed in wild-type eyes or in the known mutants of the white series. This and other compelling lines of evidence suggest that variegation is the result of somatically inherited alterations i n “gene action” rather than the result of somatic mutation (sensu stricto). The various genetic ways in which this epigenetic action is controlled raise the possibility that the control is based in nuclear processes rather than in cytoplasmic ones. (Supported by contract no. AT(ll-1)-431 of the A.E.C.) 151 K. FRANCE BAKER-COHEN, New York Zoological Society. Situs inversus and vascular asymmetry in xiphophorin fishes. (15 min.) Situs inversus viscerum, an anomaly which occurs in about one out of 10,000 humans, was found i n 37% of specimens of an inbred line of the domesticated Fury s t r a i n of the platyfish, Xiphophoms maculatus. In 4 other strains of platyfish and i n a species of the closely related swordtail, this anomaly proved to be infrequent or was not found. Examination of unborn embryos of the Fury strain revealed no evidence for twinning i n association with situs inversus, or for a positive correlation between visceral situs of mother and offspring. The asymmetry of the unpaired inferior jugular vein, which occurs in xiphophorin fishes, was found to be inverted in 10-20% of fish of all strains of platyfish and swordtails examined. In fish with situs inversus viscerum, associated inversion of the venous asymmetry occurred in ABSTRACTS most specimens (which thus were mirror images of their normal fellows in both respects). Again, as in fish with normal visceral situs, about 1020% showed (relative) inversion of the vein (or a double inversion, which thus produced normal venous asymmetry). Investigation of pedigrees led to the conclusion that both types of inversion were genetically determined, but in neither instance could a simple hypothesis for the mechanism of inheritance be fitted to the available data. Situs inversus viscerum, in the Fury strain of platyfish, was not sex linked, nor was it maternally influenced. The indications were that it was due to autosomal gene(s) lacking fidl expression. (Supported by research fellowship CF-6184 to the author and by grant C-297 to Dr. Myron Gordon from the U.S.P.H.S.) 123 ROBERT F. BALLWEG and DANIEL M. LILLY, St. John’s University, New York. Growth determinations in Paramecium caudatum by the formazan reaction. Although several species of Paramecizcm have been successfully cultivated under axenic conditions for a number of years, a satisfactory method for the quantitative determination of growth has been lacking. Ordinary turbidimetric methods used with other microorganisms could not be utilized because of the relatively low concentrations of these ciliates. Direct counts proved too tedious and time consuming for routine tests. Recent work has indicated that photometric methods using the formazan reaction are practical. Various tetrazolium salts have yielded color reactions permitting quantitative measurements proportional to growth. While such tests are actually dependent on enzymatic activity, under controlled conditions in a reproducible medium the intensity of color can also be regarded as an index of growth. The general procedures as adapted for growth studies on Paramecium caudatum are demonstrated. (Supported by grant E1506 from N.I.H., U.S.P.H.S.) 231 L. M. BARTLETT and EDWARD LIEBERMAN, University of Massachusetts. Possible visual imitation in Coturnix quail. Of 11 males deprived of food and water for 17 and 48 hours, one, designated as “instructor,” was taught to open a puzzle-box by pecking at the latch. Three “control” birds were run by trial-anderror procedure, and 7 “student” birds were allowed to observe the instructor opening the box 10 times before themselves attempting solution of the problem. No control bird solved the problem; three s t u dents did not solve the problem; the other 4 students solved the problem more quickly than the instructor had. These results indicate that some individuals may utilize visual imitation in the learning process. The species is hardy, rapidly-maturing, easy to keep, and therefore might become an important experimental animal for studies of avian behavior. 333 232 HELEN I. BATTLE and HANS W. LAALE, University of Western Ontario. Trypan blue-induced anomalies in embryos of the zebrafish (Brachydanio redo). Eggs of the zebrafish (Brachydanio rerio) at various developmental stages from cleavage to optic cup formation were exposed to the azo dye, trypan blue, in concentrations from 0.1 to 0.5% for periods from 4 to 32 hours. The dye penetrated the chorion, and although the embryos were not visibly stained, teratogenic activity was exhibited in lower concentrations when initially applied during cleavage for 20 to 28 hours; and at progressively higher concentrations with shorter exposures during blastulation and gastrulation; but t o a much lesser extent i n later stages. The malformations induced were consistent in type irrespective of the stage subjected. Anomalies of the postanal region were most apparent and involved various degrees of distortion of the notochord and musculature to a complete developmental failure of these structures. Oedema of the pericardial cavity was frequently excessive, the cardiac tube being unflexed and exhibiting an irregular and sometimes reversed beat. Vascular stasis especially i n the extra-embryonic area of the yolk sac was common together with irregularities in melanophore development and distribution. Defects i n the eye and otocysts occurred with less frequency. (This investigation was supported by Grant-in-Aid of Research A-563, National Research Council of Canada, to the senior author. ) 117 JULIAN J. BAUMEL, School of Medicine, Creighton University. The asymmetrical distribution of the posterior cerebral artery of the pigeon. (15 min.) Arterial injections were performed on 25 specimens of Columba livia. Throughout the series a consistently occurring asymmetrical conformation of the posterior cerebral arteries has been observed. The terminal segment of the posterior cerebral artery of one side (side variable) courses rostrad in the fissure between cerebral hemispheres and distributes to both hemispheres. The contralateral posterior cerebral artery terminates by coursing caudad to supply bilaterally the superior and anterior portions of the cerebellum. (Supported by research grant from the Nebraska Heart Association.) 209 H. A. BENDER and M. M. GREEN, University of Notre Dame and University of California, Berkallele eley. Effects of a suppressor of the k34k in Drosophila melanogaster. (Introduced by R. E. Gordon) (15 rnin.) The presence of a recessive suppressor mutation of the 1z34kallele increases fertility by more than three-fold, the fecundity by over 28%. Fecundity of the suppressed lzSmfemales is, however, still significantly below that of the controls. The viabiIity was not significantly different among 334 AMERICAN SOCIETY O F ZOOLOGISTS the three classes. Egg production is drastically reduced in the lz34kfemales as compared with the controls. The suppressed Zz34kfemales are intermediate. Egg-hatchabilities of 14, 35, and 73% were observed in the Z Z ~ ~suppressed ~ , and control groups respectively. Sterile lz34kfemales could be divided into two groups: those laying eggs which failed to hatch and those which failed to lay any eggs whatsoever. Analysis of the developing oocytes of the 2z34k females demonstrates an abnormally high number of yolk-filled stages by the 4th day and this condition becomes progressively more pronounced with age. Complete serial sections of paraffin-embedded female reproductive systems demonstrate that the yolk-filled follicles of many of the ovarioles degenerate by the 7th day and the lumina of the reproductive ducts fill with what appears to be necrotic yolk material. The suppressed Bemales display a similar array of pathologies which, however, are delayed in degree and time of onset. (Supported by grant CF-7015 from the U.S.P.H.S.) 182 GEORGE G. BERG and J. SZEKERCZES, University of Rochester. Trimetaphosphatase in the yolk sac of vertebrates. (15 rnin.) Trimetaphosphatase is the catalyst of the hydrolytic conversion of cyclic trimetaphosphate to linear inorganic tripolyphosphate. The metabolic significance of the reaction is still obscure, but studies on the enzyme in adult vertebrates led to the hypothesis that the enzyme is used in active transport between external and internal environment. This was tested in histochemical studies of embryos. In the chick em'bryo, trimetaphosphatase first appeared with the formation of the area vasculosa, and remained in the cytoplasm of all endodermal cells of area vasculosa through development. By the 12th day this positive lining extended all the way to the yolk stalk. Only other extraembryonic sites were some blood islands, and endodermal lining of allantois (weak stain). Embryo proper showed first trimetaphosphatase in kidney tubules at 7 days and in digestive tract lining at 14 days. Embryonic enzyme was much weaker than extraembryonic enzyme. In the mouse, extraembryonic phosphatase was localized in yolk sac endoderm and in some regions of placenta. In the embryo proper enzyme appeared only after the 9th day, becoming strongest in lining of intestine and stomach. Extraembryonic enzyme remained more active than embryonic enzyme until the 16th day. Newly hatched larvae of the minnow, Percina cuproides, showed a strong trimetaphosphatase stain only in the endodermal lining of the yolk sac, and a much weaker stain in digestive organs and kidney. We conclude that in embryos, as in adults, the sites of active uptake of nutrients for the organism are marked by a high level of trimetaphosphatase. (Supported by grant A-1089 from the U.S.P.H.S. and aided by the U. o f R. Atomic Energy Project, under contract with the A.E.C.) 94 HOWARD A. BERN and CAROLYN deROOS, University of California, Berkeley. The corticosteroids of the California sea lion (Zalophus californianus) adrenal incubated in viho. (15 min.) Adrenal glands were obtained from 10 sea lions with the help of Dr. Arthur Kelly of the Scripps Institute of Oceanography, off the Coronados Islands, Baja California. Tissues were obtained from both yearling and sexually mature indjviduals of both sexes, shortly after their death. Adrenal tissues were cut into small fragments and incubated i n the presence and absence of ACTH at 38°C in a Krebs-Ringer-bicarbonate-glucose solution (pH 7.4). The medium was extracted with ether-ethyl acetate ( 4 : l v/v), washed with 0.1 N NaOH and water, partitioned between hexane and water (1:l v/v) and chromatographed in Bush type systems. The steroids obtained were identified by standard methods including mobility in two solvent systems, ultraviolet and sulfuric acid absorption spectra, and mobility of acetylated steroids. Histologic sections of the adrenal showed definite zonae glomerulosa, fasciculata, and reticularis. Between the reticularis and the medulla are masses of eosinophilic cells, presumably cortical, which extend into the medulla in all individuals examined. lncubation of segments of the entire adrenal revealed cortisol as the major secretory product of both maIe and female sea lions. In addition, chromatograms also show appreciable amounts of compounds with mobilities similar to standard cortisone, corticosterone, and aldosterone. Results of separate incubations of capsule strippings, of cortex without the capsule, and of the medullary area will also be reported. (Aided in part by grant G-8805 N.S.F.) 45 IRWIN S. BERNSTEIN, Yerkes Laboratories of Primate Biology, Orange Park, Florida. Response to nesting materials by wild-born and captive-born chimpanzees. (15 min.) Twenty-five adult chimpanzees ranging in age from 11 to 40 years were tested with three sets of materials. Seven of these animals were wildborn and 18 were captive-born. All were tested in their home cages at the Yerkes Laboratories. The sets of materials included burlap sacks, cardboard boxes, pine straw, palmetto and palm leaves, rope, chain, plastic and rubber hose. All of the wild-born animals constructed nests during each test session, whereas only 8 of the 18 captive-born animals ever constructed nests, and 5 of these 8 never constructed anything but very crude nests and then only on one or two of the test sessions. I n addition to nest building, a variety of other activities were observed and scored. The materials were thoroughly exploited for activities described as play behavior, and all animals showed equal facility in manipulation and transportation of materials. (Supported by Army contract no. DA-49-193-MD-2093 to Dr. A. J. Riopelle.) 335 ABSTRACTS 233 WESLEY J. BIRGE and F. DONALD TIBBITTS, University of Illinois and University of Nevada. The use of sodium chloride in minimizing tissue distortion resulting from fixation by chemical means. The principal concern in this study was to determine the possible worth of sodium chloride as a fixative additament in alleviating cellular shrinkage and distortion incurred during the chemical fixation of tissues or in subsequent processing by the paraffin method. Samples of rat liver tissue were fixed in 20% neutral formalin, 20% neutral formalin/0.7% sodium chloride, Bouin’s fluid, and Bouin’s fluid! 0.7% sodium chloride. By a comparison of nuclear and cytoplasmic volumes, it was noted that in the case of formalin fixation, the addition of 0.7% sodium chloride reduced nuclear and cytoplasmic shrinkage by 18-26%. In Bouin’s fixation the addition of 0.7% sodium chloride reduced nuclear shrinkage by 7-10% and cytoplasmic shrinkage by approximately 21%. It was also shown that when the sodium chloride is omitted, 20% neutral formalin is significantly less effective than Bouin’s fluid in stabilizing the cytoplasm of liver parenchymal cells against shrinkage. In those instances in which tissue shrinkage was minimized by the addition of sodium chloride to the fixing medium, the final preparations revealed less tissue distortion and a more adequate preservation of fine detail. Following the use of sodium chloride containing fixatives, particularly formalin, the liver tissue revealed less eosinophilia in hematoxylin and eosin preparations and increased basophilia when stained with toluidine blue. This may indicate a reduction in the number of free protein amino groups in such instances, resulting in fewer binding sites for eosin and reduced protein interference to basic dye binding by nucleic acid phosphoryl groups. 180 ROBERT E. BLACK, College of William and Mary. Krebs-cycle dehydrogenases, DPNH-oxidase and cytochrome oxidase in homogenates of developing oyster-eggs. (15 min.) The respiration of whole embryos and the activities of oxidizing enzymes in homogenates have been followed in several batches of developing embryos of Crussostrea virginica. Embryos were cultured at 20”C, and aliquots were taken at the following times for the measurements: 1-2 hours (first cleavage), 8-10 hours (blastula), 23-25 hours (trochophore), and 48-50 hours (early veliger). Embryos were homogenized in 0.03 M phosphate or in a mixture of 0.37 M sucrose, 7.5% polyvinylpyrrolidone, and 0.05 M tris buffer, pH 7.4. Reduction of TPN, ferricyanide, and 2,6 dichlorophenol indophenol were measured spectrophotometrically in assays of isocitric, succinic, and alpha-ketoglutaric dehydrogenases, respectively. Oxidation of DPNH in the presence of oxalacetate or cytochrome c was followed spectrophotometrically in determining the activities of malic dehydrogenase and DPNHoxidase respectively. Cytochrome oxidase was measured manometrically in the presence of ascorbate and cytochrome c. Respiration increased 4- to 5-fold from fertilization to the trochophore stage, and no further increase occurred between 24 and 48 hours. Cytochrome oxidase, DPNH-oxidase, succinic dehydrogenase, and malic dehydrogenase did not undergo any major change during the first 24 hours, but decreases of 50 to 100% in the activities of cytochrome oxidase and DPNH-oxidase were found between 24 and 48 hours in most experiments. Isocitric dehydrogenase increased 3- to 4-fold between 9 and 24 hours, and alpha-ketoglutaric dehydrogenase increased about two-fold during this period. Between 24 and 48 hours the activity of isocitric dehydrogenase declined to 50 to 70% of the 24-hour level. (Supported by a grant from N.S.F.) 41 HELEN BLAUVELT and A. ULRIC MOORE, Upstate Medical Center in Syracuse and Cornell University. Effects of early social experience on aggressive play in young goats. (Motion picture, 15 min.) Differences in the group behavior of young kids and lambs with respect to agonistic contact and avoidance behavior is shown. The duration and nature of contact between mother and young, as a factor affecting this behavior in young goats, is analyzed. (This study was supported by a grant from the Ford Foundation.) 73 HELEN BLAUVELT and A. ULRIC MOORE, Upstate Medical Center i n Syracuse and Cornell University. Aggressive behavior in the social organization of goats and sheep. (Motion picture, 15 min.) The incidence, tempo, and form of attack and escape behavior i s illustrated in three stages of ontogeny. Postpartum contact and avoidance behavior occurs while the young still live with the mother. Complex agonistic interaction, short in duration, rapid in tempo, is seen in the social play of older kids and occurs with greater frequency than between lambs. Instances of fighting between adult goats are: dominance combat within the herd; aggression as a “greeting” to a goat new to the herd; combat between males in the mating season; aggression of a postpartum female toward goats approaching her young; and participation of the mother in the early aggressive contacts of the older kid. The adult combat in goats and sheep is compared. The use of anatomy as an instrument of combat is emphasized. (This study was supported by a grant from the Ford Foundation.) 90 BEN B. BLIVAISS, RUSSELL 0. HANSON, HELEN KUTUZOV and GERALD RIEGER, The Chicago Medical School. Pituitary ICSH in C5,BBF1 male mice treated with estradiol. (15 min.) Blivaiss et al. (Program of 1958 Meeting of Endocrine Society) reported a higher level of ICSH in pituitaries of Strain A control mice than 336 AMERICAN SOCIETY O F ZOOLOGISTS 18 ROBERT I. BOWMAN, San Francisco State College. Feeding adaptations in Galiipagos finches. (15 min.) Recent studies on Galiipagos finches (Geospizinae) have revealed fairly distinct dietary preferences that are correlated with differences in structure and behavior. Of special interest, because of conflicting opinions which have been expressed, is the functional significance of variations i n bill structure between closely related species. Food studies show that differences in size and shape of bill between closely related species of seed-eating Geospiza are correlated primarily with differences i n ability to crush hard seeds. In species of insect-eating Camarhynchus, bill differences are correlated primarily with differences in ability to cut into woody tissues. The structural basis for these functional differences is most clearly evident i n the relative size and positioning of certain adductor jaw muscles. A functional analysis of bill shape indicates that the convex curvature of the upper and lower edges of the bill is greatest in those species which grasp with the tip of the bill (Camarhynchus), straighter in those species which employ the bill for crushing (Geospiza and Platyspiza), and straightest i n those with probing bills (Cactospiza and Certhidea). The major species differences i n the skull are related to the particular mode of attack of compression and tension forces arising during feeding. The fundamental anatomical, physiological, and behavioral differences between closely related sympatric species are considered as biological adjustments to food scarcities 68 evoIved when the “forms” were in isolation. No EDWARD G. BOETTIGER, University of Connec- two islands are nearly identical in their food ticut. Length-induced changes i n the active supplies. These feeding specializations, among state of fibrillar muscle. (Introduced by C. other things, have prevented species from competLadd Prosser) (15 min.) ing for food on those islands where they now The operation of fibrillar muscle involves rather live together. special mechanical properties. Some insight into the nature of these has been revealed with the 234 use of equipment designed to produce accurately controlled transient changes i n length of 0.1 mm ELIZABETH M. BOYD and DOROTHY COVALT DUNNING, Mount Holyoke College. Metazoan in about 1 msec. Comparing results obtained in parasites of the short-tailed shrew, Blarina the large beetle, Oryctes, with the behavior of the brevicauda Say, in Western Massachusetts. bee, Bombus, it is found that two types of fibrilA survey of 23 Blarina breuicuuda Say collected lar may be described. In both a small change i n between October 1959 and March 1960 from length produced a fall i n the tension-sustaining Western Massachusetts revealed a 100% inciability of the muscle (deactivation). In Bombus this fall is transitory, the muscle spontaneously dence of ectoparasites and helminths. Ectoreactivating. In Oryctes the muscle does not re- parasites occurred on 19 hosts (82.6% ) and conturn to the pre-release activation level. The con- sisted solely of fleas and mites. Flea infestation, clusion is drawn that the length the beetle muscle represented by Ctenophthnlmus pseudogyrtes is held determines the degree of activation in- Baker was 47.8%. The precentage of mite-induced i n the muscle by tetanic stimulation. De- fested hosts was 82.5;60.9% harbored gamasids, and 52.2% trombidiform mites. The gamasids creasing length leads to a lower active state, stretching to a higher. Changes i n active state obtained were Haemogamasus alaskensis Ewing, begin after the start of change i n length. The H . liponyssoides Ewing, Eulaelaps stabularis Koch tension-sustaining ability therefore stays above (Haemogamasidae) ; Laelups alaskensis Grant (Laelaptidae); three species of digamasellids the steady state level during shortening and below during stretching. The deactivation process oc- (Gamasolaelaptidae). The trombidiform mites comprised the fur mite, Myobia simplex Ewing, curs instantaneously after a delay of 2 msec., for from three hosts; two species of Pyemotidae, one if the muscle is being stretched at this time there unidentified from a single shrew and numerous is a sharp break i n the tension and the tension specimens of Pigmephorus sp. from 9 animals; then rises less rapidly during the remainder of and Cheyletus sp. from two Blurina. Cheyletus the stretch. (Supported by grant B-186from the sp. and the digamasellids were present probably U.S.P.H.S.) i n estradiol-treated mice during induction of testicular Leydig cell tumors. To determine whether pituitaries of Strain A mice reacted differently than i n mice which are not known to develop these tumors, ICSH was measured in pituitaries of CSTBBFImale mice of which 240 received subcutaneously cholesterol pellet implants and 202 had 25% estradiol-cholesterol pellet implants starting at 1 month of age. Monthly, pituitaries were excised, acetone dried, resuspended i n saline and injected twice daily for 3% days i n C5,BBF1 male mice starting at 17 days of age and posted at 21 days. Drained seminal vesicle weights increased 113-141 % over saline controls in recipients of 2 pituitaries from 4-7 month old controls compared to 7-55% increase in recipients of 4 pituitaries from estradiol-treated mice of same age. Seminal vesicle stimulating potency of pituitaries declined to 28-60% in controls and to less than 25% in estradiol-treated animals at 10-12 months of age at above doses. The pituitary ICSH differences between C57BBF1 control and estradiol-treated mice appear similar to those observed in corresponding groups of Strain A mice. Testes of estradiol-treated CSTBBFImice showed retardation of spermatogenesis and a slight hypertrophy and hyperplasia of Leydig cells with deposition of ceroid and increased formation of reticulum fibers but no tumor development which occurs in over 80% of Strain A mice surviving 8-10 months. (Supported by The American Cancer Society, grant EDC42.) ABSTRACTS as predators. Haemogamasus liponyssoides and M. simplex are new state records for this host. The other mites constitute new host records. Helminths were collected from 22 shrews. Trematode infection was 57.5% consisting of the intestinal Brachylaima rhomboideus Sinitsin (21.7% ) and Panopistus pricei Sinitsin (43.5% ), a few immature flukes in the intestine of three and one liverfluke, Corrigia sp., o n a single host. Hymenolepidids occurred in 34.8% of Blarim as Hymenolepis sp., H. anthocephalus Van Gundy, H. blarinae Rausch and Kuns, Protogynella pauciova Oswald and P. blarinae Jones. The 91.3% nematode incidence included 47.8% encysted larval anisakids, Porrocaecum encapsulatum Schwartz and P. americanus Schwartz, and 78.3%esophageal Capillaria blarinae Ogren. 89 PAUL F. BRANDE and E. KNOBIL, Harvard Medical School. The effect of simian and bovine growth hormone on the incorporation of amino acids into protein. (15 min.) It has been observed (Kostyo and Knobil, Endocrinology, 65: 527, 1959) that the addition of simian growth hormone to isolated diaphragms from hypophysectomized rats at concentrations of 10 to 100 pg per ml of incubation medium s i m cantly increases the incorporation of leucine-2-C14 into diaphragm protein. The addition of porcine and bovine growth hormone preparations at these concentrations and under identical experimental conditions was without significant effect. These observations have been extended to the in vitro effects of simian and bovine growth hormone (10 and 50 pg per ml) on the incorporation of glycine-2-Cx4, phenylalanine-3-Cl4, and glutamic a~id-2-C'~as well as a l e ~ c i n e - 2 - Cinto ~ ~ the diaphragm protein of hypophysectomized rats. The earlier observation regarding leucine incorporation was confirmed. At the higher concentrations, simian and bovine growth hormone were equally effective in stimulating the incorporation of glycine into protein, but only the simian preparation was active at the 10 pg/ml level. Bovine growth hormone failed to increase the incorporation of phenylalanine at the concentrations used whereas the simian hormone was effective, at least at the higher concentration. Neither hormone stimulated the incorporation of glutamic acid. The significance of these findings will be discussed. (Supported by grant A-3754 from the U.S.P.H.S. and a post-doctoral fellowship to P.F.B. from the National Heart Institute.) 35 JORGE A. BRAUN-CANTILO, GILLES LA ROCHE and JOHN H. LAWRENCE, University of California, Berkeley. Conversion of testosterone to estrogens in the human female. (15 min.) As early as 1931 Steinach and Kun (Arch. Ges. Physiol., 227: 266, 1931) suggested that the ovary or the testes can produce either androgens or estrogens. This view was also supported by Lipschutz (Nature, 140: 892, 1937) and Hill (Endocrinology, 21: 495, 1937; 21: 633, 1937). By treating adrenalectomized and oophorectomized humans with massive doses of testosterone, 337 West, Damast, Sarro and Pearson (J. Biol. Chem., 218: 409, 1956) were able to observe increased amounts of urinary estrone and estradiol. In this experiment, doses of 100-200 mg of unlabeled testosterone were used; therefore, a stimulation of independent pathways of estrogen formation cannot be ruled out. The only direct evidence for the in vivo conversion of labeled testosterone to labeled estrogens was demonstrated in the pregnant mare by Heard, Jellinck and O'Donnell (Endocrinology, 57: 200, 1955). An attempt was made to study the possibility of a similar conversion in a human female with evidence of pituitary impairment as indicated by a lowering of urinary gonadotropins. Following the development of metastatic breast cancer, treated by oophorectomy and pituitary irradiation (Lawrence et al., Medicine in Japan, 5: 859, 1959; Tobias et al., Univ. of Calif. Rad. Lab. Rep., no. UCRL-3035, 1955; McCombs, Radiol., 68: 797, 1957), resulting in a remission of cancer, the patient was administered an intravenous infusion of 14 pc of 4-C14-testosterone. For a period of 10 days which followed, the urine and feces were collected for analysis. Urine samples were hydrolized by bacterial p-glucuronidase, extracted three times with diethyl ether : ethyl acetate (4:1), and the extracts were treated as to either include or exclude the phenolic estrogens. Feces samples were lyophilized, prior to separate extraction in diethyl ether, ethyl acetate, and n-butanol. The various extracts were chromatographed on methanol washed Whatman no. 20 and developed in two different solvent systems : benzene : methanol : water (11:7:2) or methanol : hexane (10: 11.5). Estrogen and androgen standards were run for comparison. The visualization of steroid fractionation was made by Folin-Ciocalteau, m-dinitrobenzene and autographic reactions. In most instances, small but detectable amounts of radioactivity appeared on the chromatograms at the level of estrogenic material. In addition, liquid scintillation counting of various fractions furnished evidence in support of a direct conversion of testosterone to estrogens. 167 D. ROBERT BREBBIA, Fordham University. Electrocardiogram of the housefly, Musca domestics, L. (Introduced by D. Ludwig) (15 min.) Relatively little information exists with regard to insect electrocardiograms. The most complete study was performed on the grasshopper, Melanoplus differentialis (Jahn, T., L. and F. Crescitelli, J. Cell. and Comp. Physiol., 10: 1937; Crescitelli, F. and T. L. Jahn, J. Cell. and Comp. Physiol., 11: 1938). More recently, action potentials have been obtained from the cicada heart (Irisawa, A., A. F. Irisawa and T. Kadotani, Jap. J. Physiol., 6: 2, 1956). Measurement of the action potential of the heart of M. domestica should provide specific information regarding the action of ions on the cardiac muscle, which would aid in developing a satisfactory insect saline solution. 338 AMERICAN SOCIETY OF ZOOLOGISTS Extracellular electrocardiograms were measured from in situ preparations of adult hearts by means of a glass microcapillary electrode connected to a cathode ray oscilloscope (CRO) through a preamplifier. The effects of various concentrations of Na, K and Ca ions on the electrocardiogram were determined by perfusion of a saline in which one ion concentration was varied, while the other two were maintained constant. Electrocardiographic tracings were photographed from the CRO screen. A n analysis of the ECG in a normal perfusate indicates a rapid, diphasic action potential. However, this wave may be fractionated into a complex of three or more components by the addition of cold saline. Gradations in spike height and duration occur during perfusion with varying concentrations of the individual ions, each ion producing a characteristic change in the electrical potential. 76 JANE VAN ZANDT BROWER, Amherst College. The reactions of Southern toads ( B u f o terrest r i s ) to honeybees ( A p i s mellifica) and their Syrphid fly mimics (Eristalis sp.). (Motion picture, 15 rnin.) Experiments were conducted to test the effectiveness of mimicry of honeybees by syrphid fiies. Five experimental toads were each given a sequence of 10 live honeybees. Four learned to reject them on sight after being stung while attempting to eat them, but ate mealworms regularly throughout the experiments as did 5 control toads. The latter were each given 10 de-stung live honeybees which they generally ate, showing that de-stung bees are palatable. Both experimental and control toads were then given random series of 50% normal and de-stung honeybees, respectively, and 50% syrphid flies. The control toads ate syrphid flies to a significantly greater extent alone. This is attributed to the laboratory experience of the experimental toads with intact honeybees and indicates that once a toad has learned 49 that they are noxious, it also rejects the syrphid IRVING BRICK, New York University. Quantita- fly mimics. tive effects of pituitary activity on melanophore 75 development in Ambystoma maculatum. (InLINCOLN P. BROWER, Amherst College. Ecologitroduced by H. Clark Dalton) (15 rnin.) cal similarity and cannibalistic interaction in Embryos of Ambystoma maculatum with two, the Monarch and Queen butterflies, Danaus one or no pituitary glands were provided by applexippus and D. berenice. (Motion picture, propriate operative treatment and used to analyze 15 min.) the relationship between pituitary activity and Egg cannibalism by hatching larvae of the establishment of early larval pigment pattern. Queen butterfly was found to be a density-dependMaintenance of punctate melanophores in hypo- ent phenomenon and therefore can have the physectomized, and hyperexpansion of melano- property of regulating population size. The Monphores in implanted animals, was evidence for arch is likewise cannibalistic, but to a lesser exabsence of pituitary activity in the former and tent. When the two were interacted in the laboexcess pituitary activity i n the latter. Melano- ratory, the Monarch cannibalized the Queen to the phore counts were made from serial sections at same extent as itself. The Queen ate the Mon20 and 40 days post-operation i n anterior and arch less than itself but still more often than posterior head and in flank areas. Monarchs ate Monarchs. It is likely that canniThe effect of pituitary activity on melanophore balism occurs to a significant extent in natural development varies with epidermal and dermal populations in the wintering grounds of the melanophores, body region and time in develop- Monarch in southern Florida where eggs of the ment. There are anterior-posterior and dorso- two species were found abundantly together on ventral differences in developmental response to the same foodplants. The possible significance pituitary hormone with reference to melanophore of this interaction with respect to the origin of number, rates ok change and proportions between migration in one of the two ecologically similar epidermal and dermal melanophores. Melano- species (the Monarch) is discussed. phore number is directly related to pituitary activity. Dennal melanophores are more dependent 95 on pituitary activity than epidermal melanophores. There is a greater reduction of dermal LINCOLN P. BROWER and FLORENCE P. CRANSTON, Amherst College and Harvard than epidermal melanophores in hypophysecMedical School. A quantitative study of the tomized as compared to control larvae. O n the courtship behavior in the Queen butterfly, other hand dermal as compared to epidermal Danaus berenice (Cramer). (Motion picture, melanophores increase in response to two pitui15 min.) taries at the same or higher rate depending on skin region. This indicates differences in minimum Over 50 virgin females of known age were rerequirements between dermal and epidermal leased singly in a natural area in southern Flormelanophores and differences in extent of their ida containing wild males and the ensuing beresponsiveness to pituitary hormone. The evi- havior was observed, filmed, and tape recorded dence indicates that the pituitary does not act verbally. The courtship follows the well known directly on melanoblasts and melanophores but stimulus-response reaction chain. When released, through the skin or skin-melanoblast-melanophore the female is pursued by a male. During this complex. Regional differences in response of aerial phase, the male extrudes abdominal hair melanophores is considered a consequence of re- pencils posteriorly which disseminate a sweet gional differences in the integument. smelling substance over the anterior of the fe- ABSTRACTS male. She then settles upon available herbage and is in turn lit upon laterally by the male. The latter alternately strokes her anterior with left and right antennae and then copulation occurs, followed by a post-copulatory flight. Several ways in which the female may be non-receptive were discovered. In the male, the functional relationship of the extrusable hair pencils to sex pockets on the wings into which they can be pushed, remains obscure. (Supported by grant 8707 from N.S.F.) 105 JOHN M. CAIRNS, Roswell Park Memorial Institute. Depth of penetration of growth-stimulating factor from apical ectodermal ridge into the limb bud mesoderm of the chick. (15 min.) The apical ectodermal ridge of the chick, when transplanted to proximal levels of another bud, has been shown to stimulate a new outgrowth which may develop into a complete limb (Zwilling, ’56). The ectodermal ridge does not influence the leg or wing quality of such a limb. In fact, even very small groups of leg mesoderm cells, grafted to the apex of the wing bud, retain their “leg” quality and form typical toes (Saunders, Cairns and Gasseling, ’57). Thus, if the apical ectodermal ridge of a leg bud plus a thin layer of subjacent mesoderm is dissected free and grafted to the dorsal surface of a wing bud, and the growth-stimulating influence from the ridge passes through the included leg mesoderm, it will act on the host wing mesoderm. The resultant accessory outgrowth should then form leg elements distally and wing elements proximally. When a sufficient thickness of leg mesoderm is included so that the growth-stimulating action is entirely contained within it, the outgrowth will form only leg elements. Experiments to test penetration in this manner, using stage 19 embryos, indicate that the growth-stimulating influence does in fact operate through approximately 0.10 mm of mesoderm. The results indicate strongly a sharply localized apical growth zone. (Supported by grant P-231 from the American Cancer Society.) 38 BYRON A. CAMPBELL and JACK R. PICKLEMAN, Princeton University. The imprinting object as a reinforcing stimulus. (15 min.) The purpose of the present experiment was to determine whether an object to which a chick had been imprinted could serve as a reinforcing stimulus in an instrumental learning situation. To answer this question, chicks were imprinted to a cardboard cube, and, following imprinting, the cube was used as a reward in a T-maze. Nonimprinted control subjects were also tested. The acquisition curves for the imprinted group were typical instrumental response curves showing a significant increase in both the percentage of correct responses and in speed of running to the goal box. The control group, on the other hand, showed neither an increase in responses to either goal box nor an increase in running speed during training. This finding was interpreted as indicating that the imprinting procedure endows 339 a previously neutral environmental stimulus with reinforcing properties. 78 C. R. CARPENTER, Pennsylvania State University. Population analysis, group composition and behavior of the howler monkeys (Alouatta palliata) of Barro Colorado Island in 1959. (15 min.) A 5th census of the howler monkey population of Barro Colorado Island, Canal Zone, was conducted during June and July 1959. Methods and procedures included systematic and consecutive area surveys, sound localization, use of anchor or reference groups, group analysis, field tape recorders and motion picture photography. Efforts were made to make another complete census of this primate population which was determined to have at least 814 animals compared with 237 found by Collias and Southwick in 1951. The increase in the population was correlated with increases in the numbers of animals in organized groups. Furthermore, the composition of groups was found to correspond more closely to the grouping patterns observed in 1932-33 than with the “reduced” population pattern of 1951. Several important changes in social behavior were observed. 137 ESTHER CARPENTER and ANN K. HOLMGREN, Smith College. The effect of excess vitamin A on the basal metabolism and on the histology of the thyroid and anterior pituitary glands of young female rats. (15 min.) At 35 days of age, three pairs of littermate rats were placed on a purified diet supplemented with adequate amounts of vitamins. From the 42nd to 56th days experimental rats received 93 to 107 units of vitamin A per gram of body weight; from the 56th to 70th days 164 to 275 units; thereafter 318 to 369 units until the 73rd day for that of the second pair, and the 85th day for that of the third pair. Calculated on the basis of oxygen used per 100 gm of body weight, the basal metabolism cjf the first excess vitamin A rat was almost as high as the control’s on the 65th day; higher on the 70th (terminal) day. For the second it was higher than the control’s on the 56th, 63rd and 72nd days. For the third it was higher on the 71st, 75th, 77th, 78th, 79th and 82nd days. A lower reading was obtained on the 84th day for reasons undetermined. As previously noted by Carpenter and Sampson (’56) sections of thyroids of hypervitaminotic-A rats were strikingly different from those of controls: central follicles were smaller and more numerous; colloid stained more unevenly and was frequently vacuolated; follicular cells were usually higher and more convex at the surface. Thyrotrophs were more easily identified in pituitary glands fixed in mercuric chloride-form01 than in those h e d in Susa. They appeared to be more deeply stained in the glands of hypervitaminotic-A rats. Preliminary counts on two sets showed a decrease in the number of thyrotrophs in glands of excess vitamin A rats. 340 AMERICAN SOCIETY OF ZOOLOGISTS 86 MELBOURNE R. CARRIKER, University of North Carolina and Institute of Fisheries Research, Morehead City. Comparative functional morphology of the boring mechanism i n boring gastropods. Boring gastropods penetrate shell of prey chemo-mechanically: radula removes fragments softened by secretion from accessory boring organ (abo). Abo is present i n 28 species examined, i n foot of Muricidae and tip of proboscis of Naticidae. Cap of abo in all borers consists of tall secretory epithelium different from any other i n these snails. Accessory salivary glands, though discharging into mouth, probably do not aid i n softening shell. Non-boring predatory snails lack abo and accessory salivary glands, and proboscides and radulae are equipped for tearing and pulling flesh rather than for rasping. In proboscisectomized borers resumption of boring in different individuals varied from 11th to 34th day after excision; i n abo-ectomized snails, from 8th to 25th day. Of 128 excised snails only one, which had not regenerated abo, did not resume boring. Experiments on rate of regeneration of abo and proboscis further showed that no snails resumed boring until both organs achieved miniature morphology of controls. During boring process, demonstrated i n behavioral studies snail dternates use of abo and radula. Borer rasps i n hole for few minutes, retracts proboscis and extends abo into hole, leaving abo in contact with shell up to an hour, then resumes rasping. Secretion of abo is neutral. Abos excised from 16 living species and placed on smooth shell i n moist chamber produced marks on shell surface ranging from faint etchings to slight depressions the shape and size of gland. No erosion took place under control tissues from other parts of body. Study of nature of secretion (possibly a conchiolinase or chelating agent) will be undertaken i n the future. 235 ALFRED B. CHAET, R. SELLERS and D. KENNAN, American University. Further characteristics of a burn toxin(s) from the starfish, Asterias forbesi. Evidence of a toxin(s), isolated from the coelomic fluid of scalded starfish and which is responsible for autotomy and death, has been reported previously (Chaet, 1958, Fed. Proc., Biol. Bull., Anat. Rec.). Since potassium i n high concentrations is known to be toxic, and since the toxic factor from starfish is dialyzable, potassium determinations (flame photometry) were performed comparing control and toxic coelomic fluids. Although toxin samples contained more potassium (3.6-15.9 d i m o l e s / l . ) than controls, the additional potassium does not account for the toxic effects previously described. It appears, despite the dialyzable characteristics of the toxin, that the starfish cannot secrete this toxin before it triggers the physiological mechanism of autotomy, since starfish kept under running sea water, even during injection, still autotomize in an apparent attempt to rid themselves of the noxious material. Since the autotomizing effect of toxic coelomic fluid is alleviated in the presence of ether, observations were carried out on the role of the toxin i n mucle contraction. The muscle of the starfish tube feet, as well as the muscles of the dermal pedicalaria, were stimulated by toxin. Again, as in the experiments involving autotomy, anesthetics such as ether and magnesium chloride counteracted the stimulating effect of the burn toxin. The specificity of toxin from scalded starfish was tested and shown to be lethal (injections of 0.15 cm3/gm) to starfish (Asterias vulgaris), brittle stars (Ophioderma breuispina), sea urchins (Arbacia punctulata), sand dollars (Echinuracb nius parma), marine annelids (Phascolosoma gouldii, and horseshoe crabs (Limulus polyphemus); whereas no apparent effect was observed when injected into red starfish (Henricia sanguinolenta) or sea cucumbers (Thyone briareus.) (Supported by grant A-3362 from the U.S.P.H.S. and grants 6-8718, G-12045 from N.S.F.) 219 RALPH HOLT CHENEY and CARL CASKEY SPEIDEL, Brooklyn College and University of Virginia. Differential effects of ultraviolet and x-ray gamete irradiation i n the sea urchin, Arbacia. (Motion picture, 15 min.) Detailed observations were made on early developmental stages of Arbacia following mixing eggs and sperm after various exposures to either x-rays or 2537 A ultraviolet (UV) rays. Differences i n the effects induced by these radiations became clear. (1) Although eggs exposed to x-rays (4-120 kr) exhibited clumping because of a radiation effect on the egg jelly capsules, eggs exposed to UV rays showed no clumping. (2) Eggs i n static condition exposed to UV rays and then inseminated developed eccentric fertilization membranes, complete or partial. Eggs continuously shaken during similar UV exposure developed concentric membranes. The degree of membrane elevation was inversely proportional to dosage strength, the stronger the dose the less the elevation. With very strong dosages the membranes failed to rise. Elevation of fertilization membranes on x-rayed eggs was similarly proportional to dosage strength. (3) A marked difference was noted in the comparative susceptibility of sperm and eggs to UV injury. UV-rayed sperm mixed with normal eggs gave rise to progeny much more retarded and injured than the progeny arising from UV-rayed eggs (equal dose) mixed with normal sperm. Further analysis revealed that a oneunit dose of UV to sperm roughly equaled an 8unit dose to eggs i n bringing about equivalent delayed development and injury in the progeny. Similar experiments with x-rays showed that a one-unit dose to sperm was approximately equal to a two-unit dose to eggs. The accompanying motion pictures present specific examples of differential effects resulting from UV and x-ray irradiation of gametes. (Supported by grant RG-4326(C3) to C.C.S. from the U.S.P.H.S.) ABSTRACTS 341 138 JOHN R. CORTELYOU, DePaul University. The effects of commercially prepared parathormone on calcium and phosphorus levels in unoperated Rana pipiens. (15 min.) Five units of parathormone (Paroidin, ParkeDavis) were administered to unoperated Rana pipiens on alternate days for 14 days. Calcium and phosphorus levels were determined daily in plasma and urine. No significant changes occurred in plasma calcium within 14 days even when the animals were given 10 units of Paroidin. Increases in plasma calcium have been observed in some mammals treated with parathormone. However, after Paroidin injection in R. pipiens urine calcium increased from 0.27 mg/100 ml to 0.43 mg/100 ml within 24 hours. Repeated Paroidin injections maintained the hypercalciuria for the remaining 12 days. The induction of hypercalciuria under these conditions is of interest in view of previous observations in our laboratories that total parathyroidectomy of R. pipiens also causes hypercalciuria. The decrease in plasma phosphorus following parathormone administration to mammals was also observed in Paroidin-treated R. pipiens whose plasma phosphorus changed from 3.93 mg/100 ml to approximately 2.50 mg/100 ml for the 14day experimental period. Except for an initial increase in urine phosphorus within the first 24 hours (2.39 mg/100 ml to 3.24 mg/100 ml) there was no evidence of a prolonged hyperphosphaturia. (Supported by grant G-5670 from N.S.F.) from U.S.P.H.S. and N.S.F. Institute No. E0/3/ 25-0436.) 224 J. C. CROSS, Texas Technological College. A virus-like substance produced in vitro. (15 min.) Litmus milk has been used as a medium for bacterial cultures for many years. However, the medium has shown a tendency to "spoil" if the process of sterilization is not properly controlled. In a study of this phenomenon methylene blue and methyiene blue thiocyanate were used as oxidation-reduction indicators instead of litmus. Samples of milk intensely colored with one of the dyes were hermetically sealed in Pyrex glass tubes with a column of air about half the length of the column of milk. The milk was carefully sterilized by a n intermittent method that would not bring about spoiling. Such milk can be kept sterile indefinitely without reduction of the dye. If the sterile milk is properly treated in a n autoclave or with high voltage electricity, a virus-like substance can be produced that can be subcultured in other tubes as bacteria are subcultured. The metabolic activity can be kept going for many days. One culture produced by autoclave continued to show activity for more than 90 days. It was kept in a dark cabinet at room temperature (25-30°C) during the 90-day period. Particles within the size range of viruses and suspected as being the cause of the metabolic activity have been photographed with an electron microscope. The research indicates that viruses might arise de novo in suitable environments. (Supported by grant 1603X from Texas Technological College.) 222 WILLIAM B. COSGROVE and MIKE McSWAIN, University of Georgia. Absence of the kinetoplast in trypanosomids of insects. (10 min.) Examination of the culture forms of 7 species, representing the genera Leptomonas, Crithidia and Blastocrithidia, of trypanosomids from insects showed that in all species a small percentage of the population (0.1-0.5% ) lacks the kinetoplast. These akinetoplastic individuals possess neither the central Feulgen-positive component nor the peripheral Feulgen-negative component. They appear normal in all other morphological features. When Crithidia fasciculata i s grown in the presence of acriflavin, the percentage of akinetoplastic individuals increases to 25-30% in the highest concentrations of the drug which permit multiplication of the flagellate. Lower concentrations produce smaller percentages of akinetoplastic individuals. The loss of the kinetoplast appears to result from failure of the structure to divide during cell division; no effect of the drug on the size of the kinetoplast in normal individuals can be detected. Inability to obtain colonies of akinetoplastic individuals from plates inoculated with populations containing 30% such individuals and failure to find dividing akinetoplastic individuals in stained preparations from acriflavincontaining cultures suggest that these individuals are incapable of cell division, at least in media which support excellent growth of normal individuals. (Supported by grant E-2701 110 SEARS CROWELL, Indiana University. Nonregulative differentiation in the thecate hydroid, Campanularia. (15 min.) In athecate hydroids a developing hydranth becomes functional when it is tiny and has only 4 to 6 tentacles; it later increases its mass 10- to 100-fold and adds tentacles. In contrast, a hydranth in thecate species differentiates from a bud nearly as massive as the adult hydranth; all tentacles develop together, none are added later, and hydranths do not grow. The following experiments on thecate hydroid, Campanularia fiexuosa, indicate rapid non-regulative differentiation. Dissociated tissues of stem, stolon, and early hydranth bud reconstitute a new hydranth equally well. Tissue derived from hydranths, however, is incapable of reorganization. Most pertinent is the observation that tissue derived from an intermediate stage of hydranth development forms irregular masses which quickly develop hydranth structures : irregularly placed tentacles and sometimes a hypostome. When a hydranth bud is cut into two parts, each develops in accordance with prospective fate. For example, the larger piece may produce a hydranth, complete except for a gap with 8 tentacles missing, and the smaller may become only a little whorl of 8 tentacles. An isolated early bud continues to grow distally through utilization of its more basal portion. It secretes a hydrotheca, inside which there is finally 342 AMERICAN SOCIETY OF ZOOLOGISTS only a thin disc of most distal tissue. The latter then differentiates only distal-most parts: i.e., hypostome and tentacles. The observation that removed tentacles and hypostome do not regenerate is further evidence that differentiation of a hydranth in Campanularia is quick, thorough, and final. (This work was supported by grant H-1948 from the U.S.P.H.S.) 236 SEARS CROWELL and MAURICE HARTMAN, Indiana University. Reorganization capacities of dissociated tissues of Campanularia pexuosa. The ability of hydroids to reconstitute has been known for many years, but most studies have been on hydra on on athecate hydroids. The following experiments were performed by the second author using the thecate hydroid Campanularia. Tissue squeezed from perisarc and teased apart is reduced to small clumps of cells which, when pushed together, soon fuse and produce a spheroidal, two-layered, hollow structure. Four t6 6 days later this may produce a hydranth. Although very small organized spheres can be produced, a minimum size of about 180 ,u diameter is necessary for the subsequent production of a hydranth. The larger the sphere, the larger the derived hydranth and the greater the number of tentacles. Tissue from stem, stolon, and early hydranth bud have the same ability to reconstitute. Mature hydranth tissue, however, lacks the ability to fuse together to make an organized structure. Tissue from an intermediate stage of hydranth development forms an irregular mass which produces tentacles and sometimes a hypostome within a few hours. When this same stage is cut into proximal a n d distal halves, the tissue derived from proximal halves is able to reconstitute. And in one case a hydranth was produced. The tissue from the distal halves of this intermediate stage, however, quickly produced irregular structures with tentacles. It appears that during hydranth development there is a stage and time at which the differentiation suddenly becomes determined. (This work was supported in part by grant H-1948 from the U.S.P.H.S.) 19 D. DWIGHT DAVIS, Chicago Natural History Museum. The feeding mechanism in mammals. (15 rnin.) The morphology of the jaw apparatus and associated structures of mammals differs more from that of typical reptiles than the reptilian apparatus differs from that of fishes. Involved are jaw suspension, differentiation of dentition, development of a secondary palate, simplification of hyobranchial skeleton, remodelling of masticatory musculature, and development of a mobile muscular tongue, fleshy lips, and muscular cheeks. The fossil record shows that these changes took place gradually and orthogenetically among several stocks of therapsid reptiles. The question of why this revolution came about has scarcely been examined. From the functional standpoint there was a profound change of emphasis: in typical reptiles the function of the mouth is prehension, whereas in mammals it is primarily mechanical reduction of food and only secondarily prehension. The cheek teeth actually reduce the food, but efficient use of these tools requires a mechanism for keeping the food in position between the toothrows. This mechanism is the tongue, cheeks and lips. A free mobile tongue, fleshy lips, muscular cheeks, and a secondary palate are the really radical, and functionally significant, innovations in the mammalian masticatory apparatus. The secondary palate permits breathing during mastication. These innovations were probably primarily responsible for the morphological revolution represented by the mammalian masticatory apparatus. Differentiation of dentition and elimination of all jaw elements except the dentary would then represent secondary refinements conditioned by the primary step. The new temporomandibular articulation and rebuilding of the middle ear, in turn, would be tertiary effects conditioned by step 2. 192 DOMINIC DEGIUSTI and EUGENE BIEGELMAN, Wayne State University. The pH of the gut of the amphipods Hyalella azteca and Gammarus sp. (12 min.) Experimental work with parasites using the amphipods, Hyalella azteca and Gammarus sp., as intermediate hosts necessitated the determination of the pH within the lumen of the anatomical segments of the gut of these animals. Preliminary trials demonstrated that the indicators Bromphenol blue, Bromcresol purple, and Neutral red could be fed to these amphipods with little evidence of toxicity. These indicators gave sharp color change and, therefore, easily interpretable and consistent results. For feeding, the desired indicator was adsorbed onto yeast cells or combined into a jell made of a 2:3 ratio of agar and gelatin. The resulting indicator feed was given to the animals as the exclusive food item. The experimental animals were kept in small aquaria at 23°C and allowed to feed over a period of 72 hours. Readings were taken at 24, 48, and 72 hours. The tests were read by rapidly removing the entire gut from the living amphipod and immediately observing with the aid of a dissecting microscope the color of each section of the gut. This color was visually compared to the standard for the particular indicator used i n the test and the pH was thus obtained. The results in pH units were as follows: Hyalella azteca. Hepatic cecae, 3.8 to 4.8; stomatodeum and anterior gut, 4.1 to 4.7; midgut 6.8 to 7.2; hindgut, rectum and proctodeum 7.2 to 7.7. Gammarus sp. Hepatic cecae 3.8 to 4.8; stomatodeum and anterior gut 4.1 to 6.3;midgut 6.4 to 7.2; hindgut, rectum and proctodeum 7.2 to 7.9. (Supported by grant E-1026 from the U.S.P.H.S.) 12 ROBERT H. DENISON, Chicago Natural History Museum. Feeding mechanisms of Agnatha, Acanthodii and Placodermi. (15 min.) The ancestors of vertebrates probably fed on microscopic food suspended i n sea water by means of a cilia-induced current and mucus en- ABSTRACTS I . tanglement of particles. Many invertebrates and protochordates feed in this manner. Among jawless vertebrates the ammocoete larva of lampreys still employs mucus entanglement, but the water current is produced by muscles instead of cilia. Adult cyclostomes are highly specialized, lampreys being parasites on other fishes, and hagfishes being scavengers. Fossil Agnatha of the Silurian and Devonian periods fed in various ways. Typical Osteostraci were probably benthonic mud swallowers similar to some living catfishes. Anaspida may have been suctorial feeders, perhaps parasites of scavengers like living cyclostomes. Among Heterostraci, pteraspids and cyathaspids probably had a protrusible mouth with which they fed selectively on the bottom. The possibilities for feeding adaptation, especially for predation, were greatly increased when jaws with gill-arch skeletons were evolved. The history of this evolution is completely unknown. Even the aphetohyoidan stage is improbable in Acanthodii, though some Placodermi may have had a free hyoid. Acanthodii, the earliest gnathostomes and the first known predaceous vertebrates, show a very limited range of feeding adaptation. Placodermi during their Devonian history became adapted to many different methods of feeding. 343 comparable to aldosterone. Age and sex differences in the corticosteroid secretory pattern of the gull will also be reported. (Predoctoral Fellow of the National Institute of Arthritis and Metabolic Diseases, U.S.P.H.S. Aided in part by grant 6-8805 from N.S.F.) 62 GEORGE W. deVILLAFRANCA, Smith College. Some properties of the contractile proteins from frog and horseshoe crab muscle. (15 min.) Numerous different extraction procedures known to remove myosin with only traces of actin from rabbit muscle have, when applied to frog and Limutus muscle, extracted actomyosin as judged by the viscosity response upon the addition of ATP. Among the extractants employed some contained ATP or pyrophosphate which supposedly dissociates myosin from actin allowing the myosin to go into solution. Our failure to obtain myosin by direct extraction suggests that the filamentous arrangement of the proteins or the interprotein binding is different from rabbit muscle. Actomyosin from these animals, partially purified by two precipitations from KC1, exhibited the following properties: drop in viscosity with ATP; super-precipitation in low KC1 solutions when ATP was added; threads which contracted with 93 ATP; and good ATPase activity. Both ATPases ROGER deROOS, University of California, are Ca+ + activated (optimal concentration, 5 Berkeley. The corticosteroids of bird adrenals mM) and Mg++ inhibited (all concentrations) investigated by in vitro incubation. (Intro- even a t ionic strengths where actomyosin is in duced by S. Nandi) (15 min.) the gel form. Also i n contrast to the rabbit system Little information is presently available o n the is the fact that increasing KC1 concentrations adrenocortical secretory products of birds. The result in decreased enzyme activity. The pH optima are in the neighborhood of 9.0 for both adrenal secretory pattern in three avian species from three different orders: domestic fowl (Gal- over a wide range of Ca++ and KCl concentralus domesticus), domestic pigeon (Columbia tions. It is of some interest that both enzymes are completely inactivated by 10-15 minutes a t Zivia), and the Western gull ( L a m s occidentalis), temperatures above 50°C although optimal activhas been studied in detail by in vitro incubation ity occurs at about 35°C. Activity at 25°C in of adrenal tissue. The adrenals from 3-12 birds 5 mM C a + + , 0.06 M KCl, and pH 9.0 (0.05 M were incubated in a Krebs-Ringer-bicarbonate medium with 250 mg% glucose after gassing histidine buffer) runs about 2000 pg P/mg protein/ hour for the frog and 300 for the horsewith 95% 02-5% COZ for 5 minutes (pH 7.8), shoe crab. (Supportedby grant A-2647 from the with and without added mammalian ACTH. The U.S.P.H.S.) medium was extracted ether: ethyl acetate ( 4 : l v/v), washed with 0.1 N NaOH and with water, 237 partitioned between hexane and water (I :1 v/v), ROBERT M. DEWITT, University of Florida. Glyand chromatographed in Bush type systems. cogen levels in fresh and starved Uniomerus Identification of the resulting steroids was based obesus, a freshwater bivalve. on standard methods, including mobility in two solvent systems, ultraviolet absorption spectra, Quantitive determinations of glycogen in whole sulfuric acid spectra, and mobility of the acety- clams were made on fresh material and on anilated steroids. mals starved for 6 and 12 months at room temThe in vitro secretory pattern is similar for the perature. Whole clams were homogenized in a three species investigated. Corticosterone is the Virtis homogenizer in 5% TCA. Aliquots of the major secretory product with aldosterone present TCA extract were treated with 95% ethyl alcohol in smaller quantities. Results to date indicate to precipitate the glycogen. The determinations that the ratio of corticosterone to aldosterone is were made by use of anthrone reagent following between 5 : l and 15:l when the adrenals are the procedure of Carroll, Longley and Roe (1956). Six individuals in each category were analyzed incubated in the presence of mammalian ACTH. Additional steroids were also found in the me- and the mean value for glycogen in milligrams dium in amounts less than aldosterone and have per gram of wet tissue was found to be as folbeen identified tentatively as cortisol and 11- lows: fresh material, 73; starved 6 months, 56; starved 12 months, 37. (Supported by grant dehydrocorticosterone. An unidentified steroid G-9844 from N.S.F.) less polar than cortisone is present in quantities 344 AMERICAN SOCIETY O F ZOOLOGISTS 103 WILLIAM C. DILGER, Cornell University. The evolution of agonistic, precopulatory and nestbuilding behavior i n the African parrot genus Agapomis. (15 rnin.) The 8 froms of Agapornis studied clearly demonstrate a fairly uniform evolutionary trend from the most “primitive,” cana, through to p. nigrigenis, the most “advanced.” The more “primitive” species tend to be sexually dichromatic and solitary in their breeding. The more “advanced” species tend to be sexually monochromatic and colonial in their breeding. The “primitive” species have highly evolved threat displays but little inhibition concerned with biting one another. The “advanced” species have almost no threat displays but do have highly evolved ritualized fighting and complete inhibition concerned with biting one another except on the toes. The lack of sexual dichromatism i n the “advanced’’ species is made up for in precopulatory behavior. The nest building through the same series goes from a simple pad to a cuplike structure to a completely covered nest with an entrance tunnel. 74 HUGH DINGLE, University of Michigan. Flight and swimming reflexes i n giant water bugs. (15 min.) Among the “classic” reflexes of insects is that of flight initiated by loss of tarsal contact. When giant water bugs (Benacus griseus and Lethocerus americanus; Hemiptera; Belostomatidae) were suspended free on the substrate, they swam instead of flying. In general the bugs responded to air currents by increased swimming; swimming ceased when tarsal contact, an applicator stick, was returned. A few bugs eventually flew, but only after a considerable period suspended in a fairly strong air jet. Prior to fiight, swimming was progressively inhibited. Separate receptors were found for swimming and flight; a flight receptor is located on the head, a location similar to those of flight receptors found in other insects. Receptors affecting swimming include the eyes and hair beds on the legs. In nature the bugs cling to submerged vegetation, behavior which correlates with the sufficiency of an applicator stick as tarsal contact. 168 WINIFRED W. DOANE, Yale University. Corpus allatum-complex and ovarian transplantations in the mutant female sterile ( 2 ) adipose of Drosophila . melanogaster. (Introduced by Sheila J. Counce) (15 min.) Several of the pleiotropic effects typically associated with adult females that are homozygous for the recessive factor female sterile (2) adipose (fs(Z)adp, located at 2.83 2 ) suggest an upset in the endocrinological control of reproduction and fat metabolism. These traits include: failure of some adp/adp ovaries to mature as early as wild type; slower rate of egg production per ovariole; yolk-deficiencies in developing eggs ; hypertrophy of the corpus d a t u m i n mated adp/adp females (but not in males or virgin females); and hypertrophy of the adult fat body resulting from almost double the normal lipid accumulation. By experimental manipulation of the residual genetic background, the first three of these effects may be eliminated. Thus, for transplantation experiments and for comparisons with wild type, adp/ adp females with superficially normal egg production are available. Larval and adult ovarian transplantations indicate that wild type implants inhibit fat storage by adp/adp female hosts while mutant implants do not. The sterility of adp/adp ovaries is autonomous, and wild type ovaries will develop normally in mutant hosts. Implanted wild type corpus datum-complexes do not alter the mutant fat condition. The effects of age, mating, starvation, and other factors on the size of the adult corpus allatum have been analyzed i n mutant and wild types. Hypertrophy of the corpus allatum in mated adp/adp females is an unstable condition which may be alleviated by implanted wild type ovaries or by injection of Ringer’s solution into adults. Evidence favors the view that a hormone released by normal ovaries partially regulates fat utilization in conjunction with reproductive activities of females. This hormone, deficient in adp/adp females, may also influence corpus allatum activity either directly or indirectly. (Supported by a Predoctoral Fellowship from N.S.F.) 238 ELLSWORTH C. DOUGHERTY, BJ0RN SOLBERG and D. JOANNE FERRAL, Laboratory for Gnotobiotic Studies, Berkeley, California. Axenic cultivation of a rotifer species. We can now report conditions whereunder continuous axenic cultivation of the minute monogonont Lecane inermis has recently been realized, starting late June 1960. L. inermis is thus the first of the class Rotifera to be so grown. (Recently its monoxenic cultivation with single species of bacteria was reported (Dougherty, Solberg and Harris, Anat. Rec., 137: 350, 1960; Science, 132: 416, 1960) also similar cultivation of a bdelloid, Philodina acuticomis var. odiosa; these two species became the f i s t bacteriophagous rotifers permanently established i n monoxenic culture.) All media so far suitable for axenic L. inermis are minor variants of a general formula based on three groups of components: (1) a water-soluble vitamin mix (“GM-originally developed for axenic cultivation of the nematode Caenorhabditis briggsae) ; (2) dilute Horlick’s malted milk (final concentrations 0.050.075% ); and (3) a heated (lamb) liver extract (HLE) at low concentrations (ca. 3 4 % full strength). HLE, originally devised by Dr. Francis W. Sayre (Laboratory of Comparative Biology, Kaiser Foundation Research Institute) for studies on C. briggsae, is prepared by a rigid formula of relatively gentle heating of a lamb liver homogdistilled water); enate (equal parts, w/v, liver this homogenate is brought quickly to 53”C, stirred 6 minutes, cooled rapidly, and spun on a Sorval high-speed centrifuge, and the resulting supernatant is sterilized by ultrafiltration. L. inermis is now i n its 4th serial culture. A chem- + ABSTRACTS ically defined (holidic) medium for its axenic cultivation can now be sought. (Supported i n part by grants 6-6018 and 6-13138 from N.S.F.) 345 toral process, was selected because here the photoreceptors are fairly uniform cylinders. Among them lie the retinal melanocytes, similarly cylindrical and of about the same size at this level. Although the two types of cells are not evenly 120 E. LLOYD DuBRUL and DANIEL M. LASKIN, distributed, being arranged in bundles, counts of University of Illinois. Preadaptive potentiality their nuclei indicated that they occur in approximately equal numbers. I conclude, therefore, of the mammalian skull. (15 min.) that there are about 2500 of each kind. AssumIt has been clearly demonstrated in widely di- ing that the 250 nerve fibers in the parietal nerve versi6ed orders of mammals that specific changes (Eakin and Westfall, J. Biophys. Biochem. Cytol., i n skull structure always accompany trends to- Oct., 1960) are axons of ganglion cells, it follows ward upright posture. A study specially planned that there are roughly 10 receptors to each ganas a “natural experiment,” with rigorous control glion cell, which is funneling i n the order of sequences of extant and extinct species (DuBrul, magnitude characteristic of cones in the human ’50; DuBrul and Sicher, ’54), exposed the crucial lateral eye. (Supported by grant 7097 from question: “HOWis the basic mammalian skull N.S.F.) equipped to respond, always in the same way, to 174 shifts toward upright posture?” An “artificial experiment” was then devised to ROGER 0. ECKERT, Columbia University. Role of stretch receptor system in crayfish swimming answer the question. Rats were used because reflex. (Introduced by E. S. Hodgson) (15 their mature skulls are extremely symmetrical min.) rectilinear structures. Any deviation from the In situ stimulation of a pair of dorsal abdombox-like form is seen immediately. Also, the generalized cranial base has sharply defined inal receptor muscles (RMs) reflexly inhibits growth sites at symmetrically intercalated carti- the output of adjacent receptors by way of the peripheral inhibitor neurons impinging on those lage plates. When the spheno-occipital synchondrosis was receptors [Eckert, Anat. Rec., 137: 351 19601. Moreover, the stimulated receptor reflexly inhibits removed, all the classical postural changes of the back of the skull appeared. They are: (1) an itself to approximately the same extent, thereby increased vaulting of the dorsum, ( 2 ) a ventral ruling out a “contrast” function for the system’s shift of the foramen magnum and occipital reflex inhibition. Simultaneous recordings were made from a condyles, (3) a ventral migration of the nuchal crest, (4) a change to a kyphotic or internally nerve supplying the extensor muscles and from the intact nerve leading to the contralateral RMs. convex cranial base, (5) a swinging of the bulla or pyramid of the temporal complex from sagittal Artificial stretching of the RM unit, and the resulting afferent activity, is associated with an toward coronal plane. Thus the primitive array of serially placed car- inhibition of extensor neuron activity during tail tilage plates along the skull base is an admirable extension. This same inhibition is seen to an preadaptive plan. The likeliest explanation for even greater degree if the tail is forced into a this extraordinary constancy in skull changes is flexed (RM stimulating) position during active that mutating genes can change the relative tail extension. growth of skull segments through the agency of In the light of this and other evidence to be these cartilagenous target sites, to curve the presented, it is proposed that the R M s may contribute to the control of the swimming reflex in cranium to the upright form. the following manner: (1) Extensor neuron activity brings about contraction of extensor mus239 RICHARD M. EAKIN, University of California, cles and RMs, raising sensitivity of the latter Berkeley. Number of photoreceptors and mel- while extending the tail. ( 2 ) Giant axon activaanocytes i n the third eye of the lizard, Scelo- tion of the powerful flexor muscles initiates tail flexion, causing an intense RM response to the porus occidentalis. initial portion of flexion. (3) This RM output The number of photoreceptors and retinal mel- centrally inhibits extensor neurons. The remainanocytes in the parietal eye of the Western Fence der of flexion is thus unopposed. (4) Inhibitory Lizard, namely 5000, was estimated by dividing feedback reaches receptor dendrites, diminishing the area (15,000 p 2 ) of the retina at the level of RM output, thereby stopping central inhibition the ellipsoid of the photoreceptors by the cross- of extensors. ( 5 ) Uninhibited extensor neurons sectional area ( 3 p 2 ) of a photoreceptor or mel- extend tail in readiness for next flexion. Further anocyte. To obtain the first datum it was as- evidence indicates that there is also a central consumed that the eye is a hemisphere. Arcs through trol of extensor timing. (Aided by U.S.P.H.S. the retina do indeed approximate semicircles. grant E-2271(Cl) and fellowship BF-8653-Cl.) The radius (50 p) of an imaginary hemisphere, the surface of which passes through the ellipsoids, 121 was measured with ocular micrometer on a TILLY EDINGER, Harvard University. Behavioral sagittal section of an adult eye, and from this specialization reflected in brain morphology. the surface area was calculated. The second (10 min.) datum was determined after measuring the averThe f i s t fossil that revealed the existence of age diameter of the ellipsoid on electron microSirenia before the Oligocene was neither tooth graphs. The ellipsoid, a region containing many mitochondria and lying at the base of the recep- nor bone, but stone: an Eocene natural endo- 346 AMERICAN SOCIETY O F ZOOLOGISTS cranial cast, its form very similar to that of the dugong brain which is unique among living mammals. Brains of pterosaurs differed much as do bird brains from those of creeping reptiles, showing olfaction reduced and vision dominant. The mammals that conquered the night sky, reducing olfaction and building up an acoustic system of singular proportions, developed a brain characteristically different from that of all other mammals. Because the oldest osseous documents of Chiroptera are Middle Eocene skeletons with microchiropteran differentiations already accomplished, earlier existence of the order is generally assumed; and because the vast majority of bats have teeth and jaws difficult to distinguish from those of Insectivora, proof of the hypothesis seemed to depend on finding, in Paleocene strata, wing-bones, the most delicate elements of mammalian skeletons. However, a natural endocast dorsally exposed in an Upper Paleocene cranial fragment reproduces the shape of the highly specialized brain that is as typical of nocturnally insect-hunting microchiropterans as are wings of the order Chiroptera. 183 ALLEN C. ENDERS, Rice University. Studies on the blastocyst of the nine-banded armadillo during the period of delayed implantation. (15 min.) During the period of delayed implantation, the single blastocyst of the nine-banded armadillo shows a high level of succinic dehydrogenase activity. Glycogen is abundant in the trophoblastic cells throughout this period, as it is in the ovum prior to ovulation. In general, little lipid is present, but some phospholipid is seen in individual cells. Alkaline phosphatase activity is light and is most readily demonstrable in the cells of the abembryonic trophoblast ( a portion of the blastocyst which does not participate in implantation). No evidence of separate organization centers within the embryonic cell mass was found by the methods used. Mitotic figures are occasionally observed in the trophoblastic cells. One blastocyst, in which the inner cell mass was necrotic, had several mitotic figures in the trophoblastic cells. Electron microscopic examination of the blastocyst reveaIs microvilli on the free surface and basal interdigitations between the trophoblastic cells. Desmosomes are common near the free surface. Mitochondria are numerous, but endoplasmic reticulum is scant. A limited number of observations on blastocysts from two other animals exhibiting delay (rat and mink) indicates that these blastocysts are histochemically quite different. (Supported by a grant from N.S.F.) 149 G. E. ERIKSON, Harvard Medical School. The vertebral column of New World primates. (15 min.) The vertebral column, fundamental in the life of an animal, is a key structure in the understanding of its biology. For most of the New World primates only fragmentary and elementary data have been published, and these have generally been based on few specimens, and seldom related to locomotor or postural matters. The present study is based on over a thousand specimens, largely in the author's collection, including all the genera and a wide range of species and ages. A functional analysis of the platyrrhine spine as related to locomotor types is attempted. This analysis is expressed in terms of trunk length (absolute and relative to limbs; total vertebral number), trunk proportions (numbers and shapes of vertebrae; relative lengths of cervical, thoracic, lumbar, sacral and caudal regions). The definition of the lumbar region on the basis of articuIation types and of the position of the anticlinal vertebra is of greater significance for the analysis of locomotion than one based on absence of ribs. The correlations between measurements taken on fresh cadavera (directly and on xray a m ) , dried articulated spines, and reassembled dissarticulated spines allows coniparisons of specimens of rarer genera in these various states. (Supported by a grant from the Wenner-Gren Foundation and grant G-13003 from N.S.F.) 181 ZANE E. ESTES, Yale University. Cytochrome oxidase activity of intact and digitonin-treated chick liver mitochondria during development. (Introduced by E. J. Boell) (15 min.) Cytochrome oxidase activity was investigated in intact and fragmented chick liver mitochondria at a series of closely spaced developmental stages. Mitochondria were isolated by differential centrifugation at 24,000 x G in 0.25 M sucrose in phosphate buffer, pH 7.4, and washed twice. They wcre broken up (presumably into sub-mitochondrial particles) by homogenization of the mitochondrial pellet in a saturated, aqueous solution of digitonin. Such sub-mitochondrial particles were sedimented by centrifugation at 100,000 x G for 25 minutes. Cytochrome oxidase activity was measured manometrically in a first order reaction by the method of Slater-involving the determination of oxygen consumption at 4 different sub-saturation concentrations of cytochrome c, each kept reduced by 0.03 M p-phenylenediamine. Oxygen uptake at infinite substrate concentration was determined by the extrapolation procedure of Lineweaver and Burk. Results with intact mitochondria show that the QOZ (PI OZ/hour/pg mitochondria1 nitrogen) at 37.5"C increases from values of 2 in 7-day embryos to 5 at 13 days incubation. It then remains constant until 17 days incubation when it undergoes a further increase. A value of 7.5 is attained at one day post-hatching. The QOZ then slowly decreases to a value of 6.5 at 11 days post-hatching, followed by a rapid decline to 4 at 13 days and 3 at 17 days, where it remains at subsequent stages. Digitonin-treated mitochondria show a QOZof approximately 15 at all stages from 7 days incubation to 27 days post-hatching. The implications of these results with respect to developmental changes in enzyme-substrate relationships will be discussed. (Supported on part by N.S.F. grant 8771.) ABSTRACTS 347 trose-treated groups demonstrated lower mortality than control groups despite the increased weight losses observed. In enzyme studies with salamanders surviving for two months glycerophosphate oxidation was extremely low in livers of all groups. Lactic dehydrogenase and malic dehydrogenase activities were appreciable, with malic dehydrogenase consistently higher than lactic dehydrogenase in all groups. With Lipomul and Sustagen malic dehydrogenase was elevated above control levels, while levels in dextrose-treated salamanders approximated control values. No marked differences in lactic dehydrogenase could be noted among the experimental and control groups. It appears that Lipomul is most effective in sustaining body weight in fasted salamanders without producing diminution in metabolic activity. (Aided by grants H-2670 and H-3027 (Rl), W.S.P.H.S.) 111 G. FANKHAUSER, Princeton University. The development of diploid and triploid embryos of Tritums (Diemyctylus) viridescens grafted under the skin of adults of the same species. (15 min.) Embryos of Triturus viridescens, when implanted with their jelly under the skin of the lower jaw of an adult newt, are invariably resorbed. Implanted without jelly, they usually develop into teratoma-like structures (Fankhauser and Stonesifer, ’56). The experiments have been continued over the past years to study the development of embryos and young larvae implanted at various stages and to compare the reaction of diploid and tiploid embryos. In most cases, vascularization of the graft by the host takes place early and leads to rapid growth of the graft which may continue more slowly for several months. Grafts have re217 tained their maximum size for up to three years. DOROTHY EVENSTEIN, GEORGE H. FRIED, In other cases they have regressed slowly. SOPHIE JAKOWSKA, SAMUEL KOOPERSTEIN The structure of the grafts is always abnormal, and WILLIAM ANTOPOL, Levy Foundation although the main body axis often remains disLaboratories, Beth Israel Hospital and Medical tinct. All grafts lose their epidermal covering; Department, Port of New York Authority. the skin forms closed vesicles below the surface Effects of injected nutrient supplements on of the graft; following metamorphosis of the weights, oxygen consumptions and respiratory graft skin, molt layers are shed into the cavity of enzyme levels of fasted salamanders. (15 these vesicles. No two grafts are exactly alike in min.) structure. Most frequently found are connective Metabolic patterns of fasted salamanders, tissue, cartilage, bone, muscle, spinal cord and Diemictylus viridescens, and their modifications brain, ear capsules, parts of the digestive tube, with injected nutrient materials were studied. and mesonephric tubules. There is no indication Dextrose, Sustagen (Mead Johnson) or Lipomul of invasive growth of graft cells into the surround(Upjohn) were injected weekly into two or more ing host tissues. Triploid embryos as grafts degroups of 4 salamanders each. Weights, oxygen velop in essentially the same manner as diploids. consumptions, and liver enzyme activities of In the abnormal environment of an adult host, the sacrsced animals were determined and con- triploid cells, though they are larger, demonstrate trasted with controls. Body weight losses for a again their equivalence to the diploid. (Sup5-week period averaged 15% of original weight in ported by grants from the Gustavus and Louise control animals, 25% in dextrose-treated animals, PfeiEer Research Foundation.) and only 4% in the Lipomul-treated groups. 196 Weight losses in Sustagen-treated animals were similar to controls. Periodic oxygen consumptions WILLIAM A. FEDER,Agricultural Research Service, U.S. Department of Agriculture, Orlando, were determined manometrically for each group Florida. Osmotic destruction of plant parasitic and expressed as deviations from control values. and saprophytic nematodes by the addition of Significant elevations in oxygen consumption sugars to soil. (10 min.) above controls occurred with dextrose, variable Up to 100% of the plant parasitic and saprorises were noted with Lipomul, while no consistent effects were observed with Sustagen. Dex- phytic nematodes were killed when sucrose or 30 LLEWELLYN T. EVANS, Research Laboratory, Jaf€rey Center, N. H. Neuroendocrine mechanisms i n courtship of a turtIe. ( 1 5 min.) In the box turtle, Terrupene curolina triunguis, the basic pattern characteristic of all the subspecies T. carolinu is observed. However, the subspecific difference from this familar pattern lies in the significance of the brilliantly pigmented orange throat of the male which appears to be the major male releaser in preliminary courtship. The male simply moves to a stop within 30 cm of a female, raises his head, pulsates his throat as in normal breathing, by expanding and contracting the gular pouch, and waits. Soon the female comes alongside, and mounting occurs. The male was not observed to bite or butt the carapace of the female before mounting, or bite at her nuchal plates after mounting and her posterior plastron had closed tightly upon his rear claws (as in T. c. buuri or T. c. Carolina). Instead, the male’s head remains raised and the throat pulsates. The female usually watches the male in this phase. Such behavior occurs in identical fashion, (1) normally in the spring season, or (2) in late summer 40 minutes or less after oral administration of methyl testosterone (Wyeth) to the male. This confirms similar results with lizards (Evans, L. T., Anat. Rec., 128: 545, 1957), and suggests that the behavioral response preceded the hypertrophic changes in the reproductive structures, since no histological differences were apparent between treated and untreated males in late summer. Apparently, androgen sensitized the CNS so that when the female’s image made impact upon his retina and brain, the male shifted from inactivity to ardent courtship. 348 AMERICAN SOCIETY O F ZOOLOGISTS dextrose was added to nematode-infested soils at the rate of 1 to 5% by weight. As little as 1,000 ppm of dextrose was nematocidal. The nematocidal action seems to be caused by a n increase in the osmotic value of the soil solution resulting from the addition of sugars to the soil. The nematodes living in the more concentrated soil solution were rapidly dehydrated and destroyed. The osmotic character of the nematocidal action was demonstrated by the rapidity and character of nematode destruction and by the enhanced nematocidal activity of dextrose over sucrose. 193 JOHN CARRUTHERS FERGUSON, Cornell University. The nature of the connective tissue of the body wall, retractor harness and cardiac stomach of the starfish, Asterias forbesi. (Introduced by J. M. Anderson) (10 min.) Morphological studies confirmed previous reports that the connective tissues of the starfish body wall are composed of fine fibrils extending from small (2-5 p ) bipolar and multipolar cells with a small amount of “cementing substance” binding the fibrils into dense aggregations. The fibrils enter ossicles as fine bundles which intertwine in the outer portions of the ossicular cellular elements. The cardiac stomach “basement membrane” consists of a dense mat of connective tissue fibrils and ‘<cementsubstance” about 2 Q in thickness with the cell bodies of the fibrils interspersed within and beneath it. It i s continuous with the connective tissue elements of the retractor harness, which occur as longitudinal sheets of fibrils and associated cell bodies interspersed among muscle elements, and a peripheral group of circular and longitudinally oriented fibrils. Histochemical tests produced reactions typical of collagenous tissues i.e., staining with acid aniline dyes in acid solution, positive PAS reaction unaffected by salivary digestion, Grampositive reaction, resistance to trypsinic digestion, susceptibility to collagenase digestion, etc. Methylene blue extinction occurred at pH 4.3-4.8, in the range characteristic of vertebrate collagen. Chromatographic analysis revealed the presence of the amino acid hydroxyproline in the three structures studied. Tests with weak acetic acid on sections fixed in 70% ethanol produced rapid swelling and disintegration of most of the fibrils. It is concluded that the connective tissues of the starfish are undoubtedly collagenous in nature. The special properties conferred by this material are of importance in the peculiar normal activities of these animals, such as eversion and retraction of the cardiac stomach. 102 ROBERT W. FICKEN, Cornell University. Some aspects of behavioral evolution. (Motion picture, 15 min.) The application of evolutionary theory to behavioral research led to several hypotheses which were found to be apparently valid during an observational study of the common Grackle (Quiscnlus quiscu2a). Some displays are very rare and may be examples of displays either com- ing into being or at the verge of extinction. Some displays probably develop signal value before any modification of their form. Transitional actions (Hans Lind effect) are apparently very important in the ritualization of motor patterns in the passerines. Sexual diethesism is dependent mainly on threshold differences which may be partially learned. 240 M. FILOSA, Johns Hopkins University. The effects of ethionine on the morphogenesis of cellular slime molds. Dictyostelium discoideum and D. mucoroides were fed with E. coli on nutrient agar containing DL-ethionine. D. discoideum forms abnormal fruiting bodies (short, thick stalks, and elongated sori) on medium containing 1.2 X lod3 M ethionine and undergoes no growth on 4.8 X 10-3 M. D. mucoroides will fruit on all concentrations of ethionine tested (1.2 x M to 1.9 X 10-8 M ) but with the higher concentrations fewer fruiting bodies are formed. A spontaneous mutant (MV) of D. mucoroides was also grown on ethionine-containing media. The cells of this mutant aggregate on nutrient medium to form spherical or elongate masses which do not usually undergo morphogenesis to fruiting bodies. However, on all concentrations of ethionine tested, the MV mutant will form normal fruiting bodies. The number of fruiting M ethionine, bodies is greatest at 2.4 X while at higher concentrations there are somewhat fewer fruiting bodies. MV cells fed with E. coli that have been grown in the presence of ethionine will not form fruiting bodies. MV cells were grown for approximately 40 hours in underwater cultures containing ethionine and then washed free of bacteria and ethionine and dispensed on both plain agar and agar conM). Only those taining ethionine (2.4 X cells on the ethionine medium completed morphogenesis to fruiting bodies. When MV cells were grown in the absence of ethionine and then transferred to plain agar or agar containing ethionine, again only those cells dispensed on the ethionine-containing medium formed fruiting bodies. It appears that the ethionine produces its effect after the vegetative stage. Preliminary data on the effects of other antimetabolites have also been collected. (This work was supported by a U.S.P.H.S. postdoctoral fellowship.) 197 HAROLD E. FINLEY, Howard University. Pseudomating of Spirostomum. (15 min.) A pseudo-mating reaction in Spirostomum ambiguum is characterized by the coming together of numbers of spirostoma to form an aggregation. The size of the ag egation varies, ranging from 4 to nearly I,oof animals. One characteristic feature of the pseudo-mating reaction i s a pulsation period during which the spirostoma entwine their bodies and glide back and forth within the aggregation, as i f attempting to conjugate; but they do not conjugate. Instead, each animal undergoes two or three consecutive binary fissions. The nuclear phenomena appep to be typical of binary fission. The aggregation - ABSTRACTS persists until the end of the fission period, then it is gradually disbanded by individual. migrations. Lantern slides will show the aggregations and the details of fission. (Supported by grant E-800 (C6) from the U.S.P.H.S.) 148 KAREN S. FOWERS, W. S. TYLER, L. M. JULIAN and P. W. GREGORY, University of California, Davis. Articulation of the lumbar vertebrae in brachycephalic bovine dwarfs. (15 min.) The achondroplastic brachycephalic dwarf, also called the short-headed dwarf, or “snorter” is conditioned by heredity and occurs in most of the major beef breeds. Buchanan, Bolin, Burnham, and Eveleth (N. Dak. Ag. Exp. Sta. Bull., 403, 1956) report two types of articulation of the lumbar vertebrae in these dwarfs based upon a sample limited in number and age range. The study herein reported was made to determine the nature of the process (or processes) responsible for the development of the two articulation types. Prepared skeletons from 203 short-headed dwarfs from one day to 8 years of age provided the material; males and females were in approximately equal proportions, and steers were also represented; most were from the Hereford and Angus breeds but there were a number of Fi hybrids or back crosses which also included the Shorthorn breed. The type of articulation was not influenced by breed, sex, castration or the type of mating. The evidence indicates that the type of articulation is primarily a function of age. All animals from birth to 122 days of age exhibited the arthrodial type of articulation; the age from 123 to 488 days is a transition period, the younger animals manifest the arthrodial type, the older the trochlear type, and the remainder are in transition showing both types of articulation. One animal was found in the late state of transition, at approximately two years of age. The transition is initiated in the first lumbar vertebra and proceeds posteriorly. (This work was done in conjunction with N.S.F. through the Summer Biology Program for Secondary Schools (Miss Fowers). Conducted in collaboration with the W-1 Project and supported in part by U.S.P.H.S. A-2626.) 136 MELVIN J. FREGLY, University of Florida College of Medicine. Spontaneous activity of hypothyroid rats in cold air. (15 min.) Administration of the anti-thyroid drug, propylthiouracil (PTU), to male rats during 4 weeks had no effect on spontaneous running activity in air at 25OC. When room temperature was lowered to 8°C for 4 days, PTU-treated rats increased their activity level during the first day of exposure but decreased it thereafter. Control rats responded similarly on the first day but continued to increase activity during each subsequent day in the cold. In other experiments PTU-treated and control rats were lightly restrained and exposed acutely to air at 5°C in individual cages. A sensitive transducer converted movement of the cage to electrical impulses which were recorded simultaneously with colonic temperature on a polygraph. Mean colonic temperature of control rats decreased 2 to 3°C during the first two hours 349 of cold exposure but was maintained at this subnormal level for an additional 2.5 hours by adjustment of activity. Activity increased immediately with cold exposure and became maximal when colonic temperature fell 0.5 to 1°C. Mean colonic temperature of PTU-treated rats continued to fall throughout the cold exposure and decreased approximately 6°C in three hours. These rats also responded to cold initially with a n increase in activity which became maximal when colonic temperature fell 3 to 4°C. However, this maximal effort occurred too late to prevent further fall of colonic temperature. The results suggest that regulation of body temperature in cold air by adjustment of activity level is an important aspect of the total regulatory mechanism and that hypothyroidism alters the relationship between colonic temperature and activity level. (Supported by grant H-3503 from the U.S.P.H.S.) 43 JOHN L. FULLER, Roscoe B. Jackson Memorial Laboratory. Effects of graded and delayed experience on behavioral development in puppies. (15 min.) Experiments on restriction of experience during early development have shown persistent deleterious effects upon behavior at later ages. We have been interested in two aspects of this phenomenon: ( 1 ) how much experience (or better, how little experience) will suffice to stimulate normal psychological development; (2) can normal behavior be established if experience is postponed beyond the age during which rapid acquisition of new behavior patterns usually occurs? Results will be presented showing: ( 1 ) that very brief periods of experience are highly effective in organizing the adaptive social and manipulative responses of the puppy; (2) that puppies whose experience is delayed to 16 weeks still become socialized. However, the nature of the social relationship in delayed-experience pups is less competitive and aggressive. (Supported by the Ford Foundation and by grant MY-1775 from the U.S.P.H.S. ) 160 PAUL S. GALTSOFF, U.S. Fish and Wildlife Service, Bureau of Commercial Fisheries Biological Laboratory, Woods Hole, Mass. Physiology of reproduction in molluscs. (30 min.) The anatomy of reproductive organs in molluscs varies from a very simple type found in bivalves to a highly complex system with several accessory organs found in cephalopods. Sexual reactions follow the structural pattern. In bivalves the gonad is located near the surface of the visceral mass and the sex cells are discharged through short gonoducts. Complication arises in Unionidae in which special brood chambers are formed in the gills. In cephalopods the organs of copulation carrying spermatophores have such high development that they become independent of the parent organism (hectocotylus). Time of spawning is determined by the state of ripeness of gonads and environment. In most cases the rise of temperature stimulates spawning although the actual temperature level varies depending on species’ habitat. In several species 350 AMERICAN SOCIETY OF ZOOLOGISTS chemical stimulation by the opposite sex provokes shedding of eggs or sperm. Female spawning of oysters (Crassostrea) is characterized by rhythmic contractions of the adductor and passage of eggs through the gills. Sperm are discharged through the cloaca. While female spawning is specific (it can not be provoked by foreign sperm of other genera), the male spawning is non-specific, the males responding to eggs of other molluscs, sugars, and hormones. Tropisms play directive roles in the mating of gastropods and cephalopods. Protandry and hermaphroditism are common among bivalves and gastropods. Sex change is influenced by environment (Crepidula). In Crassostrea virginica a delayed change in male reaction produces temporary physiological intersexes in which eggs are discharged in the male fashion. 17 CARL GANS, University of Buffalo. The feeding mechanism of snakes: its possible evolution. (15 min.) It is certain that snakes evolved from small tetrapod, carnivorous reptiles. The shift to an elongate “serpentiform” body pattern resulted in a reduced diameter to length ratio of the animal and consequently i n a reduced gape per body volume. Constant intake could only result from ingestion of more, though smaller food items or from a specialization of the ingestion apparatus to allow the intake of larger prey. Many lizards manipulate large prey by “‘inertial feeding” methods; first killing by rapid shaking. The limbs are but rarely used i n the feeding sequence. Some forms develop peristaltic movements of the neck thus stretching the prey during ingestion. A similar feeding pattern exists in some primitive snakes. The major advance of the more specialized ophidian feeding systems over a lizard-like prototype lies in the shift from inertial feeding to the independent operation of the two sides of the mouth. Primary steps are (1) the separation and independent suspension of the two sides of the palatine-maxillary apparatus, (2) the increasing freedom at the mandibular symphysis, and (3) the loosening and shifting of the supratemporalquadrate-pterygoid system to provide mechanical linkage for coordinated movement between left and right, rather than dorsal and ventral halves of the jaw apparatus. Secondary modifications involve the closure of the brain-case, the shift from short pinnate to long, multiheaded parallelfibered muscles. Beyond these remains the host of structural changes documenting the remarkable adaptive radiation of the several ophidian feeding mechanisms. (Supported by grant G-9054from N.S.F.) 106 MARY T. GASSELING and JOHN W. SAUNDERS, JR., Marquette University. Further observations on the reciprocal influence of ectodermal and mesodermal factors i n the origin of limb symmetry in the chick embryo. (15 min.) In embryos of stages 18 to 25, the apical zone of the right wing bud was severed and grafted, base down and in reversed antero-pos- terior orientation, to the dorsal side of the apical zone of the right wing bud of a similar host. In 4 of 13 cases, host and donor apices each formed a single wing tip of right-hand asymmetry. In 6 specimens the host formed a single outgrowth but the grafted apex formed duplicate wing tips mirror-twinned in the radial plane and reversed dorso-ventrally (exceptionally the graft rotated so that its dorso-ventral orientation was normal). Donor apices likewise formed dual outgrowths in the remaining three cases but in addition, d u p licate wing tips, mirror-twinned and in normal dorso-ventral orientation, were formed from the host apex. It has been postulated (Zwilling, ’56; Saunders et al., ’58)that the asymmetry of the normal limb bud arises from the interaction of a mesodermal “apical ectoderm maintenance factor” and the inductive apical ectodermal ridge. In the normal limb bud, the maintenance factor, polarized with respect to the antero-posterior axis of the bud and chiefly active post-axially, maintains the inductive activity of the ridge post-axially and a single limb outgrowth results. In the present experiments the geometric relationships between the “maintenance factors” of host ‘and graft and, respectively, the apical ridge of graft and host allow the possibility of 4 centers of outgrowth as occurred i n some of the cases. (Supported by research grant 794-C4from N.S.F.) 47 CHARLES W. GIBLEY, JR., and HOWARD L. HAMILTON, Iowa State University. Action of two pyrimidines and a riboside on development of the down feather. (15 min.) Skin from chick embryos of stages 29+ to 32+ was grown in tissue cultures containing the following compounds : Barbituric acid. This close relative of uracil was inhibitory only at high concentrations (833 pg/ml) and then not consistently. Alkaline phosphatase was active, but splotchy, in the centers of affected feather loci. Peripherally, each feather area was broken into smaller centers of phosphatase activity, as though the morphogenetic field had lost control over outlying zones. Nucleoli were multiple. 2, 4-dithiopyrimidine (333 pg/ml) arrested growth of feathers with corresponding diminution i n alkaline phosphatase. Nucleoli were unaffected. The destructive effect was concentrated in the mesenchyme, with concomitant lack of organization i n the epidermis. 4, 5, 6 (5, 6 , 7)-trichloro-l-(P-D-ribofuranosyZ)benzimidazole is an inhibitor of synthesis of RNA (Tamm, ’54, ’57). A concentration of 41.6 pg/ml stopped growth. Alkaline phosphatase was present, but not localized i n feather loci. Lower concentrations (20 pg/ml) permitted growth, but not differentiation. Phosphatase was diffuse throughout the original explant. Many feather loci were subdivided into smaller centers, indicating weakening of the original field. Sections showed multiple nucleoli. The only sign of an epidermal response to the mesodermal substratum was a nodular aggregation of cells next to the basement membrane. RNA was found in both the ABSTRACTS epidermis and pulp. Ribonuclease removed all basophilia. Thus, at this low concentration, the compound did not inhibit all synthesis of RNA, but apparently interfered with the production of protein. The data agree with the theory that a n aberrant RNA has been produced which blocks synthesis of the proper kind of protein and stops morphogenesis. (Supported by grant RG-3813 (C7) from the U.S.P.H.S.) 23 PERRY W. GILBERT and STEVEN D. DOUGLAS, Cornell University. Electrocardiography of freeswimming sharks. (Motion picture, 15 rnin.) To date scant attention has been paid to the electrocardiography of sharks and electrocardiograms have never before been taken of any freeswimming elasmobranch. In this study electrocardiograms were taken of young lemon sharks, Negaprion brevirostris, approximately 1 m in length as they swam freely in a circular concrete pool 4 m in diameter and 40 cm in depth. A single exploring electrode was inserted 2-3 cm deep, close to the pericardial sac, in the mid-ventral line immediately cranial to the coracoid bar. The flexible conducting cable (Alpha wire no. 26) was then sutured to the skin at three points as it passed around the right side of the shark to the base of the first dorsal fin where it was again securely sutured. From this point the cable passed to a swivel 2 m above the center of the pool and thence to a Sanborn VisoCardiette located at the side of the pool. The indifferent electrode and ground wires were placed in the water near the edge of the pool in accordance with the method of Wilson, Johnston, Rosenbaum and Barker (Am. Heart J., 32: 277, 1946.) The shark's heart is well insulated ventrally by the coracoid bar and dorsally by the second basibranchial cartilage. Indirect and torso leads yielded no deflections, or minute deflections. Epicardial leads were therefore used, even though these yielded a current of injury. Deflections of moderate size were obtained and it was possible to determine the R-R (cardiac rate), P-R, and Q-T intervals. Cardiac rate averaged 60 per minute, the P-R interval averaged 0.22 sec., and the Q-T interval averaged 0.58 sec. (This investigation was carried out at the Lerner Marine Laboratory, Bimini, Bahamas, and was supported in part by contract Nonr401(33)NR 104-71 between the Office of Naval Research, Department of the Navy, and Cornell University.) 351 the hemolymph of mutant flies contains diffusely stained masses that are absent in normal flies; these probably represent metabolites normally mobilized outside the ovaries under corpus allatum control and utilized in yolk production, but which in these mutants become accumulated in the hemocoele because of failure in yolk deposition; (3) in three out of these 4 mutants the fat cells have fewer fat vacuoles and a more solid background; the fat cells in the fourth mutant, however, are highly hypertrophied and have much more fat than in normal flies; ( 4 ) the thoracic nephrocytes and the pericardial cells are hypertrophied; the fifth mutant in all these respects appears normal. The experiments designed to test the lethality of homozygotes as opposed to heterozygotes, besides showing no difference in this respect, also revealed that in two mutants, in the effective sperm pool of heterozygous males, the proportion of mutant sperms is 3 to 5 % more than expected. This deviation from expectation is statistically significant. (Supported in part by funds provided to the University by the American Cancer Society Institutional Grant.) 26 ERWIN GOLDBERG, CHARLES NORMAN and I. D. PORTERFIELD, West Virginia University. Studies on the metabolism of fowl spermatozoa. (15 min.) From the standpoint of both comparative and reproductive physiology, data concerning the basic metabolic characteristics of avian spermatozoa are of considerable significance. Such data are relatively scarce in the presently available literature. In this study the oxygen and glucose consumption and lactic acid production of ejaculated cock spermatozoa have been measured. Oxygen consumption was increased 30% by glucose. Although a pronounced "Pasteur effect" could be demonstrated, there was measurable lactic acid production both in the presence and absence of substrate under aerobic conditions. Respiratory M control was blocked in the presence of DNP. Also, the typical complement of cytochromes was observable in these cells, spectrophotometrically. In another series of experiments the respiratory rates of spermatozoa from 4 different breeds of cockerals were compared. Differences, possibly of genetic significance, were observed in both the endogenous 0 2 consumption and in the amount of stimulation of respiration in the presence of 54 glucose. KULBIR S. GILL, Yale University. Developmental It is possible now to use the information obphysiology of five female-sterile mutants in tained in these experiments as a baseline for Drosophila melanogaster. (Introduced by Alex- future studies on the physiology and biochemistry ander Petrunkevitch) (15 min.) of a homogeneous population of cells under a The mutants under study are x-ray induced and variety of experimental conditions. Also these data are located on the third chromosome. In one will be useful for comparison not only with the mutant the egg production is normal, but the eggs metabolism of other types of spermatozoa, but undergo an abnormal embryology and do not also with that of any specific group of cells. hatch. In the other 4 mutants the egg develop- (Supported by grant RE6339 from the National ment almost invariably stops short of yolk de- Institutes of Health. The authors wish to acposition. The female flies in these 4 mutants knowledge the aid of Karl Nestor in obtaining the show the following: ( 1 ) the corpus allatum and spermatozoa, and are indebted to C. E. Johnson the neurosecretory cells are hypertrophied; ( 2 ) and V. W. Pence for their skilled assistance) 352 AMERICAN SOCIETY OF ZOOLOGISTS 28 DALE P. J. GOLDSMITH and E. S. NASSET, University of Rochester School of Medicine and Dentistry. Gastric acid secretion in control and thyroid-fed frogs. (Introduced by C. W. Casperi) (15 min.) Rana pipiens were fed either cat food (control) or desiccated thyroid for 4-16 days. Sacs of gastric mucosa from these frogs were sled with Ringer-phosphate buffer to 25 cm pressure and shaken for three hours at 26°C in Ringer-phosphate buffer in the Warburg apparatus. Oxygen consumption was measured for 1Vz hours without stimulus and then for an additional 1% hours with 1 mg% histamine. The acid that collected in the sacs during the shaking period was determined by potentiometric titration. Oxygen consumption of unstimulated mucosae was the same in all cases. Mucosae from control frogs did not secrete acid during three hours if histamine was omitted. Acid secretion of histamine-stimulated control mucosae was high in May, lower i n June and July and quite low i n August. Acid secretion of histamine-stimulated mucosae from thyroid-fed frogs remained at a relatively constant, low level. It was considerably lower than control secretion during May, less so during June and July and elevated above control secretion during August. Acid secretion in all cases was proportional to the increase in mucosal oxygen consumption that occurred upon addition of histamine. Efficiency of energy utilization for acid secretion, as measured by the acid to excess oxygen ratio, was similar in all frogs between May and July. Efficiency of energy utilization for both control and thyroidfed frogs was somewhat lower in mucosae assayed in August. (Supported by grant 1396 from N.S.F.) 114 DONALD C. GOODMAN, University of Florida College of Medicine. Comparative studies on functional anatomy of the cerebellum. (15 min.) Morphological studies have provided much interesting data on the evolution of the cerebellum. Studies on cerebellar function, however, have been limited primarily to mammals with relatively few investigations devoted to submammalian species. Our laboratory has been studying systematically the functional anatomy of the cerebellum from a compartive viewpoint and the present paper is based on results obtained from Rana catesbeiana, Caiman sklerops and the albino rat by means of permanently implanted electrodes in the unanesthetized animal. Experimental evidence of this study supports morphological interpretations of the phylogeny of the cerebellar vermis and, further, indicates that the incipient cerebellar hemispheres of Caim a n may be represented by a more extensive lateral region of the corpus cerebelli than had been suggested previously. Based upon the experimental results from our laboratory together with data in the literature concerning cerebellar function, the theory is proposed that bilateral and reciprocal control of posture by the cerebellar hemispheres is phylo- genetically and old organization of cerebellar function, while homolateral postural control by the cerebellar hemispheres represents a more recent specialization of cerebellular function. (Supported by grant B-1548 from the U.S.P.H.S.) 39 GILBERT GOTTLIEB, Duke University. Developmental age as a baseline for determining the critical period in imprinting. (15 min.) This study contrasted the sensitivity of two baselines for the critical period. Imprinting in 65 Peking ducklings was plotted as a function of ( 1 ) post-hatch age and ( 2 ) “developmental age” (which calculates age from onset of incubation). The findings indicated no critical period in terms of 5 post-hatch age ranges from 3-27 hours. Any training (exposure) period from 8-27 hours contained more and stronger “imprinters” than the 3-7 hour range; there were no differences between the 4 age periods from 8-27 hours. Recasting the ducklings’ imprinting performance in terms of developmental age, a critical period was evident. Proportionately more of the imprinted ducklings were trained on the 27th day from the onset of incubation than on days 26 or 28. These results indicated developmental age to be more sensitive than post-hatch age for determining the critical period. (Present address: Dorothea Dix Hospital, Raleigh, N. C.) 98 BERNARD GREENBERG, Roosevelt University. Spawning and parental behavior in female pairs of the jewel fish, Hemichromis bimacuZatus Gill. (Motion picture, 15 min.) Seven homosexual female pairs were observed on 17 occasions in a total of 22 spawnings. Six times the paired females spawned the same day; 4 pairs synchronized so well that they laid rows of eggs alternately or simultaneously. Pair formation depended on responses that seemed to check aggressiveness, including a n “estrous stance” and quivering. Groups of females that did not inhibit aggressiveness developed hierarchies. In 11 spawning, both females brooded the eggs. Twice successful exchanges were made for fertilized spawn of Aequidens portalegrensis and both pairs raised the young competently for 18 and 21 days, or fully as long as heterosexual pairs. Hence female pairs of H. bimaculatus spawn largely by chance synchronization of their estrous cycles. Since no bisexual behavior could be detected, it is held unlikely that cichlids displaying the Hemichromis type of courtship can have a bisexual neuromuscular organization. (Sup ported by grant RG-4958 from the U.S.P.H.S.) 241 SYLVIA S. GREENBERG and M. J. KOPAC, Genetics Laboratory, New York Zoological Society and New York University. Melanogenic enzyme activity in xiphophorin fishes. The enzyme activity involved in melanogenesis may be conveniently studied with each of two ABSTRACTS radioactive substrates, tyrosine-Ci4and dihydroxyphe11yla1anine-C’~ (dopa). In certain experimental designs, the significance of tyrosine incorporation is difficult to assess, since its role in normal cellular metabolism cannot be separated from the specialized function of melanin synthesis. In such instances, the second substrate involved in pigment production, namely dopa, must bear the label for the demonstration of tyrosinase activity. The in vitro utilization of dopa-Ci4 was determined in tissue culture experiments in which the melanin precursor was added to the medium normally used to grow the melanomas and amelanotic melanomas of hybrid xiphophorin fishes. The cell types characteristically found in such cultures include melanocytes, melanophores, epithelial cells, fibrocytes, and macrophages: Radioautographs of the cultures demonstrated activity in the amelanotic melanocytes of the amelanotic melanomas from albino hybrids. There was no increase in chromogen, however, as the color of labeled cultures was similar to controls. Activity was also present in those macrophages and epithelial cells which contained phagocytosed pigment cell granules. Epithelial sheet cells which were devoid of pigment granules were negative. The data lend support to a previously proposed hypothesis, based on cytochemical experiments, that the albino gene of xiphophorin fishes functions as an inhibitor at the end of a series of reactions leading to polymerized melanin. It prevents the formation of an oxidized colored chromogen by means of thiol groups. Insufficiency of enzyme or substrate cannot account for the lack of pigment in albino xiphophorin fishes. (Supported by grant C4945 from the U.S.P.H.S.) 242 GILBERT S. GREENWALD, University of Washington. Gonadotrophic content of the pituitary of the lactating mouse. Swiss mice each nursing 6 young were killed several hours after parturition or on the 6th or 12th day of lactation. The luteinizing hormone (LH) activity of the mother’s pituitary was determined by injecting the pituitary intraperitoneally into 30 day old FSH-primed mice, using the induction of ovulation in the recipient mice as the end point. The pituitary on day 6 of lactation had the maximal content of LH, at a time when the reproductive tract was most inactive as judged by histological criteria (Greenwald, J. Endocrin., 1958). As little as 1/4 of the day 6 pituitary caused ovulation in 78% of the recipient mice (17 out of 22). The day 12 pituitary was intermediate in LH content between the post partum and day 6 groups. The 50% end-point for the day 12 pituitary was between Y4 and Vz pituitary equivalents while a similar end point for the day 6 pituitary fell between Ya and ?hpituitary. The 50% endpoint for the post partum pituitary was close to two pituitary equivalents. In preliminary experiments, the pituitaries of mice nursing 6 or 12 young have failed to show any differences in LH potency. 353 These experiments suggest that hormonal imbalance during lactation is due to the diminished release of gonadotrophins from the pituitary rather than reduced production of the hormones. (Supported by grant 7063 from the U.S.P.H.S.) 243 GILBERT S. GREENWALD, University of Washington. The antifertility effects in pregnant rats of a single injection of estradiol cyclopentylpropionate. Sprague-Dawley rats weighing between 240290 gm were injected subcutaneously on the morning that sperm were found in the vagina with 1.0, 5.0, or 10.0 pg of estradiol cyclopentylpropionate (Depo-estradiol). Laparotomies were performed 9-11 days p.c. and the number of corpora lutea and embryos was compared. Nineteen % of the embryos were lost after lpg of Depo-estradiol (compared to 24% in controls) while 97% were missing after 5 or 10 pg. Deciduomata formation was inhibited in most animals that received 10.0 pg of Depo-estradiol but unaffected by 5.0 fig. However, the most significant effect of Depo-estradiol was to increase tuba1 and uterine motility so that fertilized ova were expelled from the uterus by 48 hours in animals receiving 10 pg of the compound and by 96 hours with 5 pg. Thus, 5 pg of Depo-estradiol prevented implantation of the majority of embryos by accelerating the rate of transport but did not interfere with the development of a normal uterine decidual reaction. (Supported by grant 7063 from the U.S.P.H.S.The Depo-estradiol was furnished by the Upjohn Co.) 207 P. W. GREGORY, W. S. T n E R and L. M. JULIAN, University of California, Davis. Evidence that the Dexter mutant is genetically related to recessive achondroplasia. (15 min.) A registered Dexter bull, typical of the breed, was mated to several different types of achondroplastic dwarfs, most of which were presumed to be conditioned by a specific autosomal recessive gene. The progeny from short-headed dwarfs (Johnson, Harshfield and McCone, ’50) and longheaded dwarfs (Baker, Blunn and Plum, ’51) are as yet unclassified, but “Dexter” and “Kerry” types appear to be evident at 5 months of age. When the Dexter sire was mated to long-headed dwarf segregates employed to test the genetic relationships of short-headed and long-headed dwarfs, the “compact” mutant (Stonaker and Tom, ’44), and the “stumpy” mutant (Baker, Blunn and Olufa, ‘SO), two resulting Dexter “bull-dog’’ calves were aborted at 7 months and another abnormal calf produced is not yet classified. The “bull-dog” calves are phenotypically similar in general morphology and anatomical details to those produced from mating Dexters inter se. The complete fusion of the sphenooccipital synchondrosis in the ‘bull-dog” calf at a fetal age of 7 months, or earlier, is a distinctive feature. The hypothesis is advanced that these “bull-dog” calves are identical with those produced by Dexters, the Guinea cow, a n d those segregates reported in the Jersey and perhaps other 354 AMERICAN SOCIETY OF ZOOLOGISTS breeds. The hypothesis that an incompletely dominant gene conditions Dexter achondroplasia is inadequate. The whole problem of the inheritance of bovine achondroplasia is considered open. (This work was conducted i n collaboration with the W-1 Project and was supported in part by grant A-2626 from the U.S.P.H.S.) 77 JAMES V. GRIFFO, JR., Fairleigh Dickinson University. A study of homing i n the cotton mouse, Peromyscus gossypinus. (15 min.) Homing success of animals released in unnatural habitat (golf course) adjacent to their home area was less than in natural areas at comparable distances. In natural areas males homed with greater success than females from distances greater than 500 ft. In unnatural areas there was no sex difference. Repetitive liberations of successfully homing mice from the same release site on the golf course indicated that mice can learn homing pathways. Mice which had homed a number of times and were then held in laboratory captivity for periods of more than 12 weeks before being liberated at former release sites showed no decline in homing ability. Animals released in their former home ranges occupied prior to extended periods of laboratory isolation remained and maintained these areas. Animals without previous experience from artificial displacement returned to and maintained their former home ranges when released at various distances from their capture sites after prolonged laboratory isolation. It is postulated that psychological factors are the principal source of the motivation to home. Based on the degree of psychological attachment to an area small rodents may have a (1) territory; (2) home range; (3) life range. The latter is considered to be a l l the area an animal traverses during its lifetime. The mechanism for homing in P. gossypinus apparently involves random movements outside the life range with respect to the homesite and directed movements within the life range. In the latter case the animal apparently utilizes a previous familiarity (mnenotaxis) with the general area gained by exploratory wandering, home range shifting, and dispersal from the birthplace. Each of these movements apparently involves environmental imprinting. 244 LEONARD L. GROSSO, College of Saint Teresa. The effect of testosterone propionate on the weight and B-glucuronidase level of the ventral prostate and seminal vesicle of the castrate immature Wistar rat under different dietary regimes. Albino rats of the Wistar strain weighing approximately 40-50 grams were castrated and maintained on a protein free diet for 10 days starting o n the day of operation. They were then divided into 5 major groups of 12 each and placed on the following diets for three days: group 1, 18% casein; group 2, 18% 0.5% ethionine; group 3, 18% casein 1% methionine; group 4, 18% lactalbumin; group 5 , 18% gelatin. Six animals of each group each received one subcuta- + + neous injection of 0.25 mg of testosterone propionate on the 10th day. All animals were sacrificed on the 13th day. Intact, uninjected rats i n the same weight range maintained on Fox Chow served as initial controls. The weights and B-glucuronidase levels of the ventral prostate and the seminal vesicle of a l l animals were determined. Using the initial control group data as reference the weight and enzyme percentage responses of both organs were calculated. It was found that: (1) the weights and the B-glucuronidase levels of the seminal vesicle and ventral prostate of the uninjected castrate maintained on the different diets are below those of the intact animal, ( 2 ) the responses, both weight and enzyme of both organs, to the different dietary regimes are i n agreement with the accepted value of the protein (the decreasing order being: casein, lactalbumin, gelatin), (3) an increase in the weight and the total enzyme content of both organs followed the hormone injection, all responses were influenced by the diet protein, again i n accord with its value, (4) ethionine reduced the responses to testosterone propionate, ( 5 ) methionine augmented the enzyme response of both organs to testosterone propionate, but did not statistically increase organ weights. (This study carried out while a visitor at the Bureau of Biological Research, Rutgers University, was suggested by Dr. Leathem.) 155 LEONARD L. GROSSO and J. H. LEATHEM, College of St. Teresa and Rutgers University. Carcinogen-induced hepatic tumors i n mice. (Introduced by A. F. Hopper) (10 min.) Hepatic tumor induction time with carcinogens is much longer in mice than i n rats and dosage tolerance is higher in mice. To further investigate this problem, several strains of mice were studied. Adult mice, two to three months old, of both sexes were fed a purified diet containing 24% casein and 27% fat. Dimethylaminoazobenzene (0.06% ) served as the carcinogen and was fed for 6 months. Hepatic tumor incidence for Swiss, C3H and C8H X ll male mice was 0, 14 and 40% and for female mice was 0, 72 and 60% respectively. Relative liver weight was increased with drug feeding. The response of CIH female mice to dimethylaminoazobenzene at 0.03 % level was examined after 6 months. Liver and kidney alkaline phosphatase and beta glucuronidase were determined in carcinogen-fed and control mice. Enzyme concentrations i n the liver were increased by carcinogen especially when liver tumors were evident. Kidney enzymes did not increase in mice unless liver tumor was noted. (Supported by grant (2-2846 from the U.S.P.H.S.) 101 E. B. HALE, Pennsylvania State University. Role of head height in releasing sexual versus fighting behavior in turkeys. (15 min.) Forty 4-week-old turkey poults were tested by presenting dummy heads at heights of 5 or 12 inches. The poults had been reared in a larger group for 18 days after which they were individually isolated and given daily androgen in- 355 ABSTRACTS jections (1.25 mg) to induce precocious fighting and male sexual behavior. All males courted and none attacked the low head. The high head was attacked by 50% of the males and courted by the remainder. Although only approximately half the females reacted to the high head, all those reacting attacked. Females showed only slight tendencies toward male sexual behavior and consequently the few reacting to the low head gave abbreviated or ambiguous responses. Failure of certain males to attack the high head is attributed to an exceptionally strong tendency toward sexual behavior since these birds also persisted in courting live birds despite repeated attacks by the other bird. 245 R. P. HALL, New York University. Duration of sulfonamide resistance and its reversibility in Chilomonas. A strain of Chilomoms paramecium, after 12 transfers i n medium containing sulfanilamide (50 mg% ), has retained distinct resistance to the drug for 250 transfers (62 months) in drug-free medium. A similar strain, following gradual adaptation to and completion of 70 transfers in 300 mg% sulfanilamide, has shown a greater degree of resistance after 83 transfers (25 months) in drug-free medium. A change from resistance to sensitivity, induced by gradual adaptation of sulfonamide-resistant strains to p-aminobenzoic acid (up to 20 mg% ), has been reported previously (Hall, ’56). Such a strain, at first incapable of growth in 50 mg% sulfanilamide, has been adapted stepwise (5, 10, 20, 30,40,50 mg% ) to increasing concentrations and is being maintained in 50 mg% sulfanilamide. At the end of 112 transfers (28 months), sulfonamide-resistance of this formerly sensitive strain approaches but has not reached that of the first mentioned resistant strain (derived from the normal stock and adapted directly to 50 mg% sulfanilamide and then maintained i n drug-free medium for 250 transfers). 55 MAX HAMBURGH, Albert Einstein College of Medicine. Neuroembryology of “Reeler,” a neurological mutation in mice. (10 min.) The “reeler” syndrome i n mice is caused by a single recessive gene mutation. The main features of the derangement caused by the “reeler” gene are lack of muscular coordination, balancing difiiculties and tremors. Mice homozygous for the “reeler” gene show the disturbance after the 12th day of postnatal age. Mice heterozygous for the ‘‘reeler” gene behave normally. The histological analysis of “reeler” mice revealed that the organization of the cerebellum is altered in afflicted “reeler” mice. The typical appearance of the folia is missing. T h e arrangement of Purkinje cells is disturbed. The granular layer is much reduced and the area of white matter is invaded by large cells normally found only in the deep nuclei. Abnormalities in development and differentiation leading to cerebellar disorganization make their appearance soon after birth. One of the events i n the abnormal development of the cere- bella of these animals seems to be the suppression of the outer embryonic cell layer from which the granular cells of the cerebellum are proliferated. The “reeler” syndrome thus constitutes a genedetermined malformation of the central nervous system, where processes of histogenesis are interfered with as a result of a single gene mutation. (Supported by grant B-1716 from the U.S.P.H.S.) 246 LOUIS A. HANSBOROUGH and LOWELL E. DAVIS, Howard University. Differentiation of the eye primordium of the mouse in the chick embryo. The optic vesicle of the 6-day albino mouse embryo was excised, the surrounding ectoderm and mesoderm mechanically removed and then washed in several changes of Tyrode’s fluid plus horse serum. The vesicle was cut into pieces of appropriate size i n such a manner that both tapetal and sensory areas were represented. These were transplanted to the hind-brain of the 33-hour chick embryo. Mortality of the host embryos was very high, though surviving hosts provided sufficient material for a study of the behavior of both host and graft tissues. Host embryos were h e d in Bouin’s fluid from the second to the 4th day after operation. From these, sections were prepared and stained in Delafield’s hematoxylin and eosin. A study of the stained material shows that both optic cup and lens have developed from the vesicle alone or from the vesicle plus remnants of head ectoderm which may have remained in spite of attempts to remove the ectoderm by mechanical means. Both cup and lens are generally smaller than those of the control but normal in appearance. There is no clear-cut evidence of induction, though this is suggested by the relationship between lens and chick head ectoderm and the changes noted in the appearance of these ectodermal cells. A more effective method of removing the adhering cells from the vesicle and better controlled orientation of the graft i n the host will probably provide more concise information as to the role of both graft and host tissues i n forming the definitive eye. 247 LOUIS A. HANSBOROUGH and GLORIA J. WILLIAMS, Howard University. Regulation in the developing wing of the chick embryo. I. Differentiation of grafted somites. A plug of mesoderm with covering ectoderm about the size of two trunk somites was removed from the wing bud of the three-day white Leghorn chick embryo. The plug was replaced by trunk somites from donor embryos. Host embryos were h e d in Bouin’s fluid from one to 4 days after operation. From these, sections were prepared and stained i n Delafield‘s hematoxylin and eosin. A study of the stained material showed that the transplanted somites differentiated into their component parts, dematome, myotome and sclerotome. During differentiation some of the somites migrated from a superficial to a more central and dorsal position in the wing bud. In others, differentiation began at the site of trans- 356 AMERICAN SOCIETY OF ZOOLOGISTS plantation. Somite mesenchyme freely intermingled with that of the wing bud. The dermomyotomic plate was formed and later divided into its component elements. The dermal elements of the somite supplemented those of the wing bud, thus producing an abnormally thick dermis. Myoblasts and chondroblasts from the somite could not be distinguished from similar cells of the developing wing. Ten-day embryos stained for skeletal parts show that the wing bud and graft produced a wing which is essentially normal. 147 JAMES M. HARTSHORNE, Cornell University. The role of learning in the development of the Eastern Bluebird’s vocal repertoire. (15 min.) The experimental Bluebirds used in this study were taken from the wild at three main stages of development: the egg-stage, the nestling-stage, and the post-nestling-juvenile-stage. Thus, birds constituting the egg-stage category were placed in sound isolation as eggs soon after they were laid in the wild, those constituting the nestling-stage were isolated while nestlings, and those birds comprising the post-nestling-juvenile-stage were removed from the wild as juveniles and isolated at approximately two months of age. The development of vocalizations and resulting vocal repertoires of the birds in each category were then compared. It was found that learning plays but a small part in the Bluebirds’ acquisition of call notes; for all of the common calls such as those of alarm, distress, location, etc. appeared only i n the oldest age-class sampled, that is, only the post-nestlingjuveniles taken from the wild at about two months of age have produced these vocalizations. 24 PHILIP L. HAWLEY, G. EDGAR FOLK, JR. and MARY A. FOLK, State University of Iowa. In. fluence of magnesium on intact and isolated rodent hearts in hypothermia. (Motion picture, 15 min.) To elucidate the relationship between thermoregulation and the serum magnesium increase characteristic of hypothermia, a comparative study of heart rates and core temperatures of three rodents under subcutaneously injected magnesium (0.5 mg/kg) and cold stress was made. The choice of species was based on their relative abilities to hibernate in captivity: the nonhibernating Long-Evans Rat; the Golden Hamster, which may hibernate; and the 13-Lined Ground Squirrel, which hibernates readily in captivity. In two species the combined stress of magnesium and cold induced a reduction of heart rate and core temperature, rapidly in the case of the rat and more slowly in the hamster. Heart rates and core temperatures of the ground squirrel were reduced slightly, but were maintained at this level for several hours. These results implied some sort of protective role for magnesium in the hibernating animals. A question raised from this evidence was whether the heart is singled out as the major locus of magnesium sensitivity. To clarify this point a second phase consisted of repeating the study on isolated hearts of the same three species of rodents. As with the intact animals, the isolated hearts were subjected to magnesium and cold stress. The method used for obtaining electrocardiographic records of these isolated small animal hearts is shown in a movie film. (Supported by grant 6-5282from N.S.F.) 115 MAX HECHT, Queens College. The history of the frogs. (15 min.) The orthodox interpretation of the origin of the frogs states that Protobatruchus of the early Triassic represents an intermediate type between modern frogs and the ancestral group. The author believes that the resemblances between Protobatruchus and the modern frogs are clearly a case of convergence. The first known true frogs are highly evolved forms with typical anuran adaptations from the upper Jurassic. They are: Montsechobatrachus FejBrvary, Eobatrachus Marsh, Eodiscoglossus Villalta, Comobatrachus Hecht and Notobatrachus Reig. Examination of the type of Stremmia of Nopsca indicates that it is not a frog. The Jurassic anurans (relatively primitive forms) belong to a complex having leiopelmatoid and possibly some discoglossoid affinities. By the lower Cretaceous most of the major anuran lines had already evolved and the 6 major types of vertebral evolution had been completed. One of these types became extinct in the early Cretaceous. By the early Tertiary most of the modern frog genera and subfamilies had evolved. For example, Calyptocephalella (including Eophractus of Schaeffer and GigaNtobatrachus of Casamiquela) is known from the early Eocene, early, middle and late Oligocene, lower and middle Miocene, and Pleistocene. Detailed study has revealed a single allometric growth pattern which has persisted through the entire history of the genus. Only maximum size and average size have been altered. It appears that frog evolution passed through an initial rapid phase which resulted in the establishment of the major higher categories, but the history of modern species and genera i s primarily a Tertiary phenomenon. 170 JOSEPH K. HICHAR, Parsons College. Differential effect of picrotoxin on crustacean nerve cords. (15 min.) Experiments with picrotoxin and its effect on the “spontaneous” electrical activity of crustacean nerve cords seemed to indicate that picrotoxin does not have as great an excitatory effect on the very small and very large nerve fibers as it does on the intermediate-sized fibers. Pulse height analysis of the “spontaneous” action potentials was suggested as a valuable technique which would make possible the study of picrotoxin and of its selective effects, if any, on the nerve fibers contributing to this activity (Hichar, J. K., in Medical Electronics, niffe & Sons, Ltd., 1960). Using multi-channel pulse height analysis all the spontaneous activity from one abdominal ganglion was recorded simultaneously. This activity was divided into 100 sections determincd by spike amplitudes. “Normal” activity was determined followed by studies of the effects on this activity ABSTRACTS of various concentrations of picrotoxin on the abdominal ganglia of the nerve cords of the crayfish, Orconectes virilis, and of the lobster, Homarus nmericanus. Preliminary results indicate that picrotoxin does, indeed, have a greater excitatory effect on intermediate-sized fibers (about 20-30 pv in amplitude) of the lobster abdominal nerve cord. Similar results were obtained in only 25% of the experiments using crayfish abdominal ganglia except that the spike amplitudes of the affected fibers were approximately 60 pv. 150 MILTON HILDEBRAND, University of California, Davis. Relative variability of body proportions in marsupial and other mammals. (10 min.) When the morphologist finds differences in body proportions among related animals of different body size he may wish to determine by regression analysis if the proportions are correlated with size. However, adult mammals of a kind are of closely similar size so the points plotted for each population tend to cluster. Because marsupials continue to grow slowIy as adults it was thought that these animals would lend themselves to more accurate analysis. It was found that large clusters of plotted points replaced small clusters because skeletal proportions of marsupials of a kind tend to be more variable than those of eutherian mammals. This is demonstrated for 6 limb proportions of 6 marsupial and 6 eutherian populations, and for a cranial proportion of 13 marsupial and 14 eutherian populations. 248 GERTRUDE W. HINSCH and SUSAN KNOVACS, Mount Union College and Mount Holyoke College. Alkaline phosphatase in the trachea and esophagus of the developing chick. On the fourth day of development the trachea is found lying ventral to the esophagus. Mesenchyme begins condensing around the tracheal epithelium on the fifth day, at stage 37 (11 days) the first cartilaginous rings appear, and by stage 38 (12 days) all are completely formed. There is some evidence that the most anterior cartilages are formed before those more posterior. During the third week of development the trachea increases in size and the lumen becomes filled with secretion. Pseudo-stratified columnar ciliated epithelium begins to appear at 15 days. Alkaline phosphatase is highly reactive in the mesenchyme surrounding the epithelium prior to cartilage formation. After the cartilages have formed the reaction diminishes and in late stages of development phosphatase is found only in the epithelium. Development of the esophagus and its glands was described (Schumacher, Zeit. Mikr.-Anat. Forsch., 5: 1-22, 1926). Allenspach and Hamilton (Anat. Rec., 134: 525, 1959) described alkaline phosphatase activity in the ventral mesenchyme surounding the epithelium to stage 34. At stage 38 alkaline phosphatase activity appears in the basal layers of the epithelium and is subsequently lost in the mesenchymal tissues. This activity persists in the epithelium throughout development and following hatching. At 16 days 357 the glands arise as solid buds of the epithelium projecting into the tunica propria. These buds are highly positive for alkaline phosphatase. As differentiation of the glands becomes complete, they and their ducts lose their positive phosphatase reaction. (Supported by research grant A-3343(A) from the U.S.P.H.S.) 169 E. S. HODGSON, L. B. BARTON BROWNE, L. F. DODSON and J. K. KIRALY, Columbia University, Commonwealth Scientific and Industrial Research Organization and National Biological Standards Laboratories, Australia. Pharmacological properties of roach corpus cardiacum. (15 min.) Extracts of corpora cardiaca of the roach Periplaneta americana contain an adrenalin-like component which inhibits acetylcholine-induced contractions of rat uterus. Pooled extracts of up to 40 pairs of the glands were found to contain highly variable amounts of the adrenergic factor, but an effect of 10 pairs of glands comparable to adrenalin was not unusual. When the roaches were given severe electrical shock treatments prior to removal of corpora cardiaca, the adrenergic effects of the gland extracts were significantly reduced (often below the limits of detectability by this assay method). The active material is more effective on rat uterus preparations than upon rat colon, suggesting that it may be more closely related to adrenalin than to noradrenalin. Attempts to follow the presumed release of the substance into the blood stream during or after shocking failed because of the presence of a powerful, long-lasting stimulant for uterine contraction in the blood of the roach; this stimulating factor completely obscures both cholinergic and adrenergic effects of other substances upon the uterus. Effects of injections of adrenalin into roaches have been analyzed. The relative merits of chromatographic and pharmacological analyses of the extracts are considered, and the possibility that an adrenalin release mechanism may be involved in the insect’s reaction to stress is raised. (Supported by grant E-2271 from the U.S.P.H.S.) 25 JACK W. HUDSON, University of California, Los Angeles. Water requirements and thermoneutrality in the antelope ground squirrel, Citellus leucurus (15 min.) The antelope ground squirrel is a small fossorial and diurnal desert mammal which does not hibernate. It is, therefore, of interest to know whether such an animal possesses any physic+ logical adaptations to high ambient temperatures and limited water supplies. C. leucurus dies after 17 to 35 days of a dry diet. Animals can maintain weight indefinitely under laboratory conditions with water rations equal to 2% of their body weight per day. The typical ad libitum consumption is 13% of body weight per day, a value predictable from the surface area-volume relationship, I ( d / h r . ) = 0.010 gm0.88 (Adolph, Science, 109: 579). The ad libitum water consumption is constant at aII 358 AMERICAN SOCIETY OF ZOOLOGISTS ambient temperatures below 40°C, but increases at higher temperatures coincident with the onset of salivation, a heat-dissipating mechanism. The lethal ambient temperature is 42.6% The urine:serum osmotic pressure ratio of 9.4 is below the 10.7 value reported for the kangaroo rat under similar conditions ( Schmidt-Nielsen, J. Cell. and Comp. Physiol., 32: 331), and represents the maximum capacity of C. Eeucurus to conserve renal water. The evaporative water loss is similar to that of other desert rodents (The Schmidt-Nielsens, Am. J. Physiol., 262: 31) and increases as the ambient temperature increases from 30 to 42.6"C. The standard metabolism of C. leucurus is 1.03 k 0.04 cm3 Oz/gm/hr. at ambient temperatures between 30 and 37OC, a value predicted from the equation Q (Cal./gm/hr.) = 17.6 gm-0.27 (Morrison, J. Cell. and Comp. Physiol., 31: 281). A slight increase in oxygen consumption between 37 and 42.6"C is attributed to hyperthermia. It i s concluded, therefore, that the thermoneutral zone extends from 31 to 42.6"C. (This study was aided in part by a contract between the Office of Naval Research, Department of the Navy, and the University of California Nonr-233 (61).) 146 D. K. HUNTER and ROBERT K. SELANDER, University of Texas and American Museum of Natural History. Sound spectrographic analysis of a continuous singer, the mockingbird. (15 min.) The song pattern repertoire of an individual mockingbird (Mimus polgglottos) recorded at Austin, Texas, consisted of approximately 45 distinctive patterns, each of which was repeated an average of 3.84 times in sequence to form song series. Mean song series length was 4.74 seconds (range, 0.1-14.0 seconds); and inter-song series intervals averaged 1.15 seconds (0.7-2.4 seconds). No fixed pattern with respect to sequence of song patterns or number of repetitions in song series was noted; but there was some tendency for songs of similar structural type to appear i n sequence. Among renditions of the same song pattern at different times in a 40-minute period, variation was no greater than that found among songs of individual discontinuous singers, such as the Chipping Sparrow (Spizella passerina). The number of song patterns presented by a mockingbird is finite, and the individual does not sing variations ad libitum. Comparing inter-song series intervals and song series lengths, it is calculated that the mockingbird sings 80% of the performance time, as compared to 30 to 50% in the case of a discontinuous singer. The significance of this &ding i n relation to Hartshorne's theory of the "monotony threshold" is discussed. 66 WILLIAM H. JOHNSON, University of Illinois. Evidence for a dual mechanism for tonic contractions in molluscan muscles. (15 min.) Muscular contraction is usually conceived of as a two-stage process mediated by the actomyosin system in which this system actively develops tension or shortens, and then passively relaxes at a rate essentially determined by both the rate of decay of contractile activity (represented by the active state) and the forces tending to elongate the muscle. Contractions of molluscan adductor and byssal retractor muscles are often followed by an abnormally prolonged relaxation phase which is not related i n its time course to the decay of contractile activity. We have suggested, along with others, that during such tonic contractions, tension or shortening is maintained by a second system mechanically in parallel with the actomyosin system. This second system is thought to be incapable of active tension development, but, by crystallization of its protein components, to provide a mechanically rigid system which resists elongation during the relaxation phase. Thus, contraction i n these muscles is a function of the actomyosin system, while relaxation is thought to depend on a set of parallel filaments containing paramyosin. Studies on glycerinated fibers from byssus retractor muscles of Mytilus edulis have revealed the presence of mechanically continuous elements i n parallel with actomyosin filaments. These fibers respond to changes in environmental pH and ionic strength in a manner to be expected of paramyosin. At pH below 6.5 fibers are mechanically inextensible, while above pH 6.5, they are plastic. Furthermore, electron microscopic evidence reveals the presence of paramyosin periodicity in filaments of tonically contracted muscles, whereas little periodicity is seen i n relaxed muscles. Such evidence indicates that a dual mechanism is present in these muscles and could form the basis for tonic contractions. 118 MALCOLM T. JOLLIE, University of Pittsburgh. The bird pterygoid, an example of functional modikation. (15 min.) The pterygoid bone of the passerine, or the hawk, arises as a single unit which contacts the vomer anteriorly and the quadrate posteriorly. Contact with the palatine extends along the anterolateral margin for some distance. In the hawk, functional basipterygoid processes occur in the late embryonic and early nestling period, but later contact is lost and the processes atrophy. In the nestling, the anterior end of the pterygoid fuses with the palatine and a joint develops between it and the posterior part. These two segments can be referred to as the anteropterygoid (hemipterygoid or mesopterygoid of others) and the posteropterygoid. The development of the articulation is related to movement of the upper mandible. In most neognaths such movement is possible but i n others it is reduced as indicated by an incomplete joint. The significance of a jointed pterygoid may lie i n the idea that the originally mesokinetic skull of the proavian was abandoned with the origin of birds and replaced by a more delicately controlled grasping action of the bill. ABSTRACTS 249 HAROLD M. KAPLAN, Southern Illinois University. Electrophoretic analysis of protein changes during growth of Pseudemys turtles. The varying resistance to disease with age has been partly attributed to serum proteins. These proteins were compared in female Pseudemys scripta turtles whose average shell lengths were 1.5 and 7.5 inches. The blood was separated electrophoretically in Veronal buffer and the strips were analyzed in an Analytrol densitometer. Total proteins were determined by Microkjeldahl analysis and the amount of each protein fraction was computed from the estimated areas obtained in the Analytrol curve. The total serum protein rose from 1.57 gm/lOO ml in animals of 1.5 inch shell length to 6.03 gm/100 ml in animals of 7.5-inch shell length. The total proteins of the adults separated to 4 electrophoretic fractions, all of which were probably globulins. There was no evidence for albumin. The total proteins of the young turtles separated electrophoretically in a basically similar manner to that of the adults. There were, however, two subfractions of fraction I1 in one group of babies and two subfractions of fraction IV in another group. Also, the percentage of each fraction varied between the young and the adult turtles. The young turtles showed no electrophoretic evidence of serum albumin. (Supported in part by the N.S.F. Undergraduate Research Participation Program.) 359 and hypersensitive states. (Aided by funds from The Population Council, Inc., and -grant E-2651 from the U .S .P.H.S.) 213 JEROME S. KAYE, University of Rochester. Acrosome differentiation in the cricket. (15 min.) The phenomenon of acrosome formation, as it occurs during spermatogenesis in house crickets, was studied with the electron microscope. The acroblast of the earliest spermatid is cup-shaped and has the typical structure of a Golgi body-a series of parallel membranes with associated vacuoles. A “pro-acrosomic” granule, homogeneous in structure and surrounded by a membrane, forms within the cup. A t about the time of the initial elongation of the nebenkern, the pro-acrosomal granule is deposited on the nucleus, posteriorly, near the proximal centriole. During the subsequent stages of spermiogenesis, the granule both migrates to the most anterior part of the nucleus and undergoes a complex differentiation in structure. In its initial differentiation, the granule assumes the shape of a blunt cone with its base abutting against the nucleus. Then an invagination of the granule occurs at the base, and in the space created by the invagination, an entirely new structure forms which is dart-like in shape. The entire acrosome then elongates and becomes 3attened. The structure of the mature acrosome consists of two concentric cones. The outer, derived from the original pro-acrosomal granule, is a 250 thin-walled cone of elliptical cross-section. SEYMOUR KATSH, University of Colorado Med- hollow, is another flattened cone, derived from the ical Center. Mediation of immunologically-in- Within also elliptical in cross-section. (This .- in__ duced aspermatogenesis by a non-acid-fast bac- dart, vestigation was supported in part by grant RG terium. 6850 from the U.S.P.H.S.) Immunologically-induced organ-specific dyscrasias offer an excellent opportunity to study 112 inhibition of growth and development. One of these disorders, aspermatogenesis, is useful as a DOUGLAS E. KELLY and J. C. van de KAMER, University of Colorado and the Rijksuniversimodel system in our attempts to elucidate the teit, Utrecht, Netherlands. Some cytological and mechanism( s) of specifrc cell destruction during histochemical considerations on the amphibian immune response. One of the requisites for the pineal organ. (15 min.) induction of aspermatogenesis in the guinea pig Study on the development of the pineal system is the use o f complete adjuvant (8.5 ml paraffin oil, 1.5 ml emulsifier, and 5 mg of bacteria) and in Amphibia has been extended by a histochemiheretofore the only bacteria found to be con- cal and cytological analysis of the epiphysis of the sistently effective in mediating the tissue destruc- adult frog, R a m esculenta. In this form the epition have been Mycobacteria (butyricum or physis differentiates into a well-defined hollow tuberculosis). In this study 6 adult male guinea vesicle composed of various so-called sensory, pigs were injected intracutaneously in 6-8 sites parenchymal, supportive, and ganglionic cell in the nuchal region with 1.0 ml of homologous types. It is interconnected with the subcommistesticular homogenate (weighed amount of testis sural organ and the subcutaneous “Stirnorgan” by a neural tract. homogenized in an equal volume of 0.9% saline) Outer segments of pineal sensory cells proemulsified in an equal volume of the modified adjuvant, 8.5 ml Bayol F, 1.5 Arlacel A and 5 mg truding into the epiphyseal lumen can be shown of Corynebncterium rubrum. Two months after histochemically to contain sulfonic acid, glycol, injection the animals were sacrificed. The degree or perhaps acid mucopolysaccharide components of testicular damage was found to be as uni- in addition to an active lipid metabolism. The formly severe as when Mycobacteria are em- similarity of such components to those of visual ployed. Also, the ileal segments of the animals sensory cells of the retina has been considered responded in vitro to specific antigen (homologous as well as the possibility of secretion by pineal sperm) by contracting strongly. We are currently sensory cells. In many specimens, additional extracting these bacteria for active materials and cells contributing a definite follicular cysteinecomparing them with substances from Mycobac- or cystine-rich secretion have been observed. A teria in order to gain further insight as to the close similarity between this secretion and subparticipation of bacteria in autoallergic diseases commissural secretion is well-established. Inner- ’ 360 AMERICAN SOCIETY OF ZOOLOGISTS Such effects, recorded in these experiments from intact preparations using intracellular micropipettes, are often long-lasting, and frequently involve modulation of preexisting “spontaneous” activity if present. Potentiating effects of this kind include (1) extreme many/one responses, in which discharge to a single afferent volley may last for 1 second or more; ( 2 ) after-discharge, with adaptation, following a direct or synaptic tetanus; (3) classical post-tetanic potentiation (not previously found in fiber-to-fiber synaptic systems), in which either (a) threshold for spike initiation drops following the tetanus or ( b ) a volley previously evoking single spikes causes multiple discharges following the tetanus; (4) entrainment of preexisting “spontaneous” activity to a higher level, immediately following a direct or synaptic tetanus, which adapts over a period of 1-5 seconds; and (5) “tonic” increases in spontaneous activity during repetitive presynaptic stimulation with afferent volleys which evoke no fixed-latency spike(s). Inhibitory effects include (1) reduction of “spontaneous” activity following single or multiple discharges evoked synaptically, usually followed by rebound increases; ( 2 ) reduction in level of “spontaneous” activity during repetitive presynaptic stimulation (the reciprocal of (5) above); and ( 3 ) depression or abolition of “spontaneous” activity following a direct or synaptic tetanus. (Supported in part by grants B-1608 and B-1739, U.S.P.H.S.) 33 GEORGE C. KENT, JR. and SHEILA L. LYTLE, Louisiana State University. Decidual cell responses following exogenous prolactin in uterine-traumatized hamsters. (10 min.) Twenty-four pseudopregnant hamsters with bilateral uterine traumas induced with sutures the second or third night after sterile mating (s.m.) were injected intraperitoneally with 60 IU of bovine prolactin nightly, as follows: trauma the second or third night after sterile mating and prolactin commencing on night of trauma, 12 animals; trauma the second night after s.m. and prolactin commencing the third night, 6 animals; trauma on the third night after s.m. and prolactin commencing the second, 6 animals. All animals were killed on the 6th, 7th or 8th night after s.m. Twenty-one animals exhibited a decidual cell response (DCR). Of 6 animals exhibiting a DCR characterized as (+), 5 had been killed on the 5th night after s.m. The three animals exhibiting a DCR characterized as had all been killed on the 6th night after s.m. Of 12 exhibiting a 173 well developed deciduoma, 4 had been killed on DONALD KENNEDY and JAMES B. PRESTON, the 6th night and 7 on the 7th night after s.m. Stanford University and State University ColOf 13 uninjected animals traumatized the seclege of Medicine in Syracuse. Complex re- ond or third night after s.m. only three exhibited sponses of central neurons in the crayfish to a DCR One had been killed on the presynaptic and direct stimulation. (Intro- 6th night after s.m. and two on the 7th. Previous duced by Victor C. Twitty) (15 min.) efforts to induce deciduomata in uninjected hamFrequently, neurons in the crayfish nerve cord sters had been equally ineffective. Prolactin enhances the DCR in hamsters, sugshow more subtle sorts of responses to afferent (and direct) stimuli than the single- or multiple- gesting a luteotrophic effect in this species. Maxispike discharges previously described (Kennedy mal responses are observed on the 6th and 7th and Preston, J. Gen. Physiol., 43: 655, 1960). nights after s.m. Unpublished studies indicate vation of the pineal sensory cells includes not only dendritic plexuses in contact with basal processes of the cells, but also a system of loopshaped nerve endings on the cell bodies. Clusters of pineal sensory cells are invariably found with their outer segments extending into the third ventricle in the vicinity of the subcommissural organ in addition to the usual clusters whose outer segments protrude into the epiphyseal lumen. While a functional interpretation of pineal components remains obscure, these cytological and histochemical properties provide useful criteria for investigations on the cellular differentiation of the organ. (Supported by postdoctoral research fellowship BF-7283-c from the U.S.P.H.S.) 203 DONALD KENNEDY and MERLE S. BRUNO, Stanford University and Harvard University. On the spectral sensitivity of visual systems in decapod crustacea. (15 min.) The comparative biochemistry of vertebrate visual pigments has revealed interesting correlates with habitat and phylogeny; and the beginnings of such an analysis in decapod crustacea have been made by Hubbard and Wald (Nature, 180: 278, 1957), who extracted a rhododopsin from lobster eyes. This visual pigment has X max. 515 mp (difference spectrum). Using the retinal action potential recorded from intact, darkadapted lobsters as an index of sensitivity, we have measured the spectral sensitivity function for lobster vision; our measurements agree fairly closely with Hubbard and Wald’s absorption spectrum, though the sensitivity peak is shifted 5-10 mfi towards the red-due probably to the known presence of astaxanthin as a screening pigment. In the crayfish, however, the sensitivity curve is quite different; similar measurements on compound eyes of Procambarus clarkii show an extremely consistent sensitivity peak near 570 mp. This is due to a single visual pigment, since monochromatic light adaptation has no differential effect upon sensitivity. Since crayfish possess vitamin A1 exclusively, this pigment owes its long-wavelength absorption peak to a n altered protein moiety, just as does vertebrate iodopsin. The direction of the shift in maximum is the same as that between marine and fresh-water fish-the latter, like the crayfish, having sensitivity maxima displaced toward the red, but achieving this through alteration of the carotenoid component of rod and cone pigments. The caudal photoreceptor of the crayfish, however, has its sensitivity peak at 500 mp, and must therefore be utilizing a different photopigment. (++) (+++). ABSTRACTS that deciduomata induced following trauma and progesterone injections commence to degenerate on the 7th night after s.m. despite continued injections. (Prolactin supplied by the Endocrinology Study Section, N.I.H.) 34 HARRY A. KENT JR., University of Georgia. A glycostatic factor from the fallopian tube of the golden hamster. (15 min.) The influence of ovaries and fallopian tubes upon muscle glycogen level in the hamster was investigated. The biceps femoris was analyzed for glycogen content following the traditional alcohol precipitation proceedures. Final carbohydrate content was determined using the phenol method of furfural formation. Ovariectomy alone does not change muscle glycogen level from that of unoperated controls. Salpingectomy alone results in a significant increase i n muscle glycogen, while combined ovariectomy-salpingectomy results in low muscle glycogen levels. It is suggested that a factor from the ovaries tends to increase muscle glycogen while the f allopian tube factor favors maintenance of a static level of muscle glycogen. 211 ROBERT C. KING, Northwestern University. The hereditary ovarian tumors of the f e s mutant of DrosophiZa melanogaster. (15 min.) Hereditary ovarian tumors occur in females homozygous for the second chromosomal gene female-sten’le (fes). In Feulgen-stained preparations the ovarioles are seen to be subdivided into a series of sausage-shaped cell aggregates, each surrounded by an ill-defined follicular epithelium (King, Bumett and Staley, ’57). These follicles are filled with hundreds to thousands of oogonialike cells (many of which are in mitotic stages). Some metaphases are multipolar and others show high degrees of polyploidy. King, Sang and Leth (’60) reported that some cells within tumorous chambers in ovaries of certain ages can differentiate into cells which, on the basis of chromosomal morphology, resemble normal nurse cells. A positive correlation exists between the frequency of this more normal differentiation and the degree to which the residual genotype is beterozygous. Banded, polytene chromosomes are observed i n the nuclei of some of the larger, nurse-like cells. A more recent study of 16,000 chambers from f e s flies reared at 18 or 21 or 25OC demonstrated an inverse relationship between temperature and more normal differentiation. At lower temperatures not only do more chambers contain “nurse cells,” but more nurse-like cells occur per chamber. Oocytes are observed rarely, and when present yolk is often deposited in them. The frequency of yolky oocytes among chambers from flies reared at 18OC is 80 times that found in the 25” series. It is suggested that the plus allele of f e s is responsible for the formation of a substance which by promoting differentiation restricts cell division. The f e s gene is thought to be hypomorphic, and the system it controls seems to function best at low temperature i n flies of certain ages and characterized by certain residual genotypes. (Research supported by grant C- 361 5302 from the U.S.P.H.S. and by grant 6-11710 from N.S.F.) 251 C. WARD KISCHER and HOWARD L. HAMILTON, Iowa State University. Effects of respiratory inhibitors on the development of the down feather. Skin from chick embryos with incipient feather germs was grown in w i t 7 0 in the presence of 4 respiratory poisons. Histochemical determinations of alkaline phosphatase and ribonucleic acid were made on the fixed cultures. Sodium fluoride (70-140 pg/ml) inhibited the phosphatase reaction, the accumulation of RNA at the basement membrane, and development of feathers. In sections, the mesodermal condensation at each feather locus was separated from the epidermis at its lateral edges. 2,4-dinit?ophenoZ (8.33-50 pg/ml) inhibited production of feathers, but not the phosphatase or the RNA. There was evidence of necrosis in the dermis. Iodacetate (6.25-25 fig/ml) inhibited phosphatase, the build-up of RNA at the basement membrane, and morphogenesis of the feather. Sodium cyanide (16.67-125 pg/mI) stopped development of feathers, reduced the RNA at the basement membrane, but did not inhibit the phosphatase. At levels of partial inhibition the phosphatase appeared increased, but with no concurrent increase in epidermal RNA. Evidence of the morphogenetic field of the feather was seen i n the consociative polarity of fibroblasts radiating from the base of each locus. The inhibitors disturbed this polarity and, at partially-inhibitory levels, caused subdivision of the feather locus into several cellular aggregates each of which retained a strong reaction for phosphatase. The data suggest that phosphatase and other enzymes are selectively inhibited. The loss of phosphatase activity curtails morphogenesis possibly by eliminating a source of energy for the reconstruction of new kinds of RNA needed in the synthesis of specsc feather proteins. (Supported by grant RG-3813(C7) from the U.S.P.H.S.) 100 ROBERT B. KLOPMAN, Cambridge University. A motivational interpretation of the greeting display in geese. (15 min.) Greeting is perhaps the most striking display seen in the behavior of true geese and many other species of Anatidae. K. Lorenz has devoted considerable attention to greeting i n geese for he feels it an important example of the spontaneity, invariability and accumulation of action specific energy so characteristic of innate behavior patterns. He proposes that while not strictly a “vacuum activity,” greeting is largely “independent of external stimulation.“ Furthermore, Lorenz characterizes this display as a form of redirected attack. The present study indicates clearly, however, that the animal is under the influence of three conflicting tendencies: to attack, to flee from and to behave socially toward its companion(s). These results demonstrate also that specific external stimulation is necessary for the 362 AMERICAN SOCIETY OF ZOOLOGISTS release of the display. Fellowship MF-8219.) (Supported by N.I.H. 161 ALAN J. KOHN, Flordia State University. Chemoreception in gastropods. (30min.) The mechanisms by which gastropod molluscs detect chemical changes in their environment are reviewed, with special consideration given to the osphradium. The anatomy and position of this organ and the results of behavioral experiments have suggested that it functions as a chemoreceptor, but this has been disputed. In the present study, attempts were made to determine the function of the osphradium by electrophysiological methods. The results are discussed in the light of the form and distribution of the osphradium among gastropods and the relationship between the anatomy of the organ and the habits of the species. The sensitivity and responses of gastropods to inorganic salts, prey, enemies, and members of the opposite sex through the modality of chemoreception are also reviewed and correlated with ecological characteristics. 252 ALAN J. KOHN, Florida State University. Development in marine gastropod molluscs of the genus Conus and its ecological significance. Egg masses of 21 species of Conus collected in Hawaii and the tropical Indian Ocean were studied. The number of eggs per egg mass ranged from 2,000 to 1,500,000. Most species lay large numbers (> 30,000) of eggs per mass, and the eggs are of small size (125-230 p ) . The course of larval development within the egg mass was determined for 9 species. Early cleavage stages occur during the &st three days after oviposition. The trochophore stage is suppressed, a characteristic of gastropods i n which that part of development is passed in an egg capsule or brood pouch. In 7 species the trochophore stage was approximated 4-8 days after oviposition. The veliger stage is typical and occurred at 7-9 days i n 7 species and at 12-14 days i n one. Although hatching occurred in only 6 species, at 14-16 days after oviposition, it was possible to determine the stage at hatching of 15 species. Twelve, which deposit large numbers of small eggs, hatch as pelagic veligers and probably remain so for some 10,000) time. Three species lay small numbers of large (350-490p ) eggs. These hatch as nonpelagic veliconchas, which settle immediately and assume the benthic mode of life characteristic of the adult. The correlations of egg diameter, egg number, and mode of larval development support the generalizations demonstrated by Thorson Verh. Deutsch. 2001. Ges., 1951: 276-327, 1952). The signijicance of the marked difference in larval ecology within the same genus is not known. (Portions of this study carried out at the University Zoological Museum, Cophenhagen, and the Bingham Oceanographic Laboratory, Yale University, were aided by a grant-in-aid from the Sigma Xi-RESA Research Fund and by the W. W. Anderson Fellowship, respectively.) < > (< 63 DAVID R. KOMINZ, National Institutes of Health. The comparative biochemistry of tropomyosin, paramyosin, and the 3 S component of myosin. (15 min.) Three classes of muscle proteins having a sedimentation rate of about 3 S, namely tropomyosin, paramyosin, and the 3 S component of myosin, have been subjected to a comparative study employing amino-acid, end group and electrophoretic analysis. The tropomyosins of lower vertebrates and of mammalian cardiac muscle are very similar to that first purified from rabbit skeletal muscle by Bailey in 1948. However, progressive chemical differences appear in the tropomyosins of vertebrate smooth muscles, of echinodern muscle, and that of arthropods and molluscs. No tropomyosin can be isolated from annelids. A muscle component apparently peculiar to molluscs and annelids, paramyosin, differs signscantly from tropomyosin in chemical composition and in electrophoretic mobility. Specific procedures have been developed for the cleavage of the ubiquitous contractile protein, myosin, into several well-defined components. One of these, termed the 3 S component, accounts for about a quarter of the myosin. I n contrast to tropomyosins from vertebrate and arthropod muscle sources which show reciprocal changes i n lysine and arginine, the 3 S components from these sources show instead reciprocal changes i n aspartic and glutamic acids. 37 SOL KRAMER, State University of New York. Early predatory behavior in praying mantids. (15 min.) Newly emerged, first instar nymphs of Tenoderu aridifolia sinensis were isolated in vials and their reaction to Drosophila tested. At 28-30 hours of age, sometimes earlier, they fix (optic localization), strike and catch flies presented to them. Isolated nymphs 20-22 hours old often fix and strike at flies, but frequently miss on their &st, second and even third attempts. While some at this age succeed on their third or 4th attempt, others show no interest in flies. At 30 hours of age, however, 6 or 7 out of each 10 mantids isolated caught fruit flies on their first strike. This successful first strike ratio did not appear to improve when mantids 44 or 68 hours of age were presented with flies. These older, unfed mantid nymphs, however, reacted more quickly with a strike to the fly stimulus. In addition, they sometimes showed stalking behavior and actively pursued flies. 97 SOL KRAMER, State University of New York. Color changes correlated with parental behavior in cichlid fish. (15 min.) Observation of over 20 breeding pairs of Aequidens lntifrons reveals specific striking color changes correlated with parental behavior. The vertical band chromatophores of the female become conspicuously black several days before egg laying. This female coloration persists during ABSTRACTS egg laying and afterwards during egg fanning. During the --day egg incubation period most fanning is performed by the female. The male’s coloration either shows no vertical banding or a light banding. Whenever the male relieves the female in guarding and fanning the eggs, his vertical banding becomes darker, then lessens or disappears as he leaves the eggs. When the f r y begin to swim and the male participates in guarding and schooling the fry with the female, his banding intensity approximates the female’s. Most intense banding appears in both parents when they confine fry to a small territory aggressively defended against other adults in the same tank. 253 SOL KRAMER and HELMUT MUELLER, State University of New York and Cambridge University, England. Band pattern changes in insect muscles during stretch and contraction. The abdominal longitudinal muscles of the cockroach, Periplaneta americana, with a rest length of about 7 p/sarcomere appear specifically designed to undergo considerable length changes during the insect’s normal activities. These muscles, inserted in parallel bundles on the endoskeletal ridges of the segmental plates, are approximately 2 mm long. When the abdomen is severed from the thorax and opened, these muscle bundles shorten to about 1 mm. The segmental plates can be pulled apart, stretching these muscles to over 3 mm. These length changes are reversible. _ _ _ _ ~.and mav be considered to lie within physioldgical limits. Muscle bundles were secured in different states of stretch, rest length and contraction by pinning the segmental plates on paraffin. Subjected to glycerination and lyophilization, preparations were obtained which contracted on addition of ATP and water, respectively. Bundles of myofibrils were separated under a dissecting microscope, then studied with phase contrast i n a suitable medium. Measurement of band widths were made, and plotted against sarcomere lengths. The sarcomeres measured ranged from 3-12 p. Above sarcomere lengths of 5 p , increase in sarcomere length is produced by corresponding increase in I-band widths alone; the A-band remaining relatively constant (4.5 p ) . Above sarcomere lengths of 9 p, I-band increase exceeds the maximum H-band width of 2.0 p observed. At 4-5 @ sarcomere lengths, however, definite shortening of the A-band occurs. Another feature is partial overlapping of contraction band formation and the A-band curve, indicating that under these conditions contraction bands may be formed which are longer than the widths of the A-bands. (Supported by a Senior Postdoctoral Fellowship and grant 6-7248 from N.S.F., and a Research Fellowship from the American Heart Association. 79 ERNEST M. KUHINKA, Dickinson College. Consumer behavior: inner-orientation of population in a functional area. (15 min.) A previous study, a functional analysis, which described potential areas for urban expansion, was succeeded by a new survey which devoted 363 special attention to the inner structure of the functional (natural) area. This survey analyzes the intensity of the buying habits and geographical orientation of the consumers. The results of the survey described on maps, following the basic ecological principles, present spatial relationships in an easily understandable visual form. The consumers’ buying habits and behavior were surveyed from the point of view of basic economic needs, such as ( a ) grocery, ( b ) variety and hardware, ( c ) department and specialty, ( d ) recreation, ( e ) automobile, and ( f ) banking. The orientation pattern was located in South-Central Pennsylvania, including large part of the Cumberland Valley with larger population aggregations in Harrisburg, Carlisle, Shippensburg, and Chambersburg. The survey places a greater emphasis on the critical challenge of research work which could contribute greatly to the promotion of general human welfare. 254 J. V. LANDAU and J. H. McALEAR, Albany Medical College, Veterans Administration Hospital and New York State Dept. of Health, Albany. The ultrastructure of primary and FL-amnion cells following exposure to high hydrostatic pressure. The application of high hydrostatic pressure to cells in monolayer cultures results in a reversible solation of the cytoplasmic gel as expressed by a change from a normal cell shape to that of a sphere. Throughout the period of pressure application and following release of pressure, primary amnion cells retain numerous, distinct intercellular connections. As the bulk of the cytoplasm assumes a spherical shape the retention of these sites of adhesion results in a series of bridge-like connections between relatively spherical cells. Electron micrographs of these clearly defined connective sites reveal distinct, structural, intercellular bars (desmosomes). FL-strain (continuous culture) amnion cells show far less intercellular adhesiveness as a result of pressure treatment. Those sites which do maintain such contact show a considerably less degree of structural organization. Shortly after the release of pressure, FL-amnion cells undergo a decided contraction followed by vigorous bleb activity over the entire cell surface. Primary amnion cells exhibit neither of these phenomena. The bleb activity in FL-amnion has been examined with the electron microscope and determined as the formation of pseudopodia rather than a temporary appearance of cytolytic blisters. The cytoplasmic ultrastructure is continuous with that of the cell proper and the endoplasmic reticulum in most cases seems especially prominent within the pseudopodia. A comparison with non-pressurized control cells reveals no structural difference in nuclei or mitochondria. Although the formation of numerous pseudopodial blebs must involve a large increase of surface area, these experiments reveal no changes in the surface membrane which could account for such a n expansion. (Partially supported by grants from the National Cancer Institute and National Heart Institute.) 364 AMERICAN SOCIETY OF ZOOLOGISTS 36 sal to the renal vessels and adjacent to the inWILLIAM B. LANGAN, New York Medical Col- ferior vena cava. In race X the left suprarenals lege and the Food and Drug Research Labora- were more variable in position, frequently lying tories. Ovulation-inducing action of steroid farther to the left and also more caudad. Both were flattened dorsoventrally, the right pyriform hormones in Rana pipiens. (10 min.) It has been reported that progesterone, desoxy- and the left disc-shaped. Four cases of incomplete embryonic rotation of corticosterone and testosterone will induce extraseasonal ovulation in Rana pipiens (Langan, the digestive tube were observed. Proc. Soc. Exp. Biol. Med., 1941; Comparative 32 Endocrinology, ed. by Gorbman, 1959). In order to better characterize the biological J. H. LEATHEM, Rutgers University. Reproductive organ responses to estrogen in rodents. nature of steroids possessing this action, a series (10 min.) of 34 steroids were tested. RUM pipiens were procured from Vermont durTestes of adult male desert rats (Dipodomys ing March and April and stored at 8°C. During spectabilis) averaged 639 mg and comprised 0.55 experiments, frogs were housed in glass bowls at mg/100 gm body weight. The adult laboratory temperatures ranging from 15" to 22°C. Steroids rat testes averaged 2832 mg and comprised 0.89 were carried in sesame oil and administered by a mg/100 gm body weight. Water, glycogen and single intraperitoneal injection. Dosages ranged cholesterol concentrations of 85.0%, 0.06% and from one to 4 milligrams. Ovulation was deter- 0.20%, respectively, were comparable in the two mined by stripping and sacrificing for abdominal rodents. Administration of estradiol benzoate subinspection. cutaneously daily for 20 days to the laboratory rat The following steroids were effective: desoxy- in 0.1 mg amounts will increase pituitary and corticosterone; 3-(3-0~0-17~-hydroxy-4-androstenadrenal weights but will depress the reproductive 17a-yl) propionic acid y lactone and its 19 nor organs. Estradiol benzoate in daily dosages of analogue, progesterone; 17 methyl 19-nortesto- 50 pg was administered to 8 desert rats. Hyposterone; testosterone; methyl testosterone; vinyl physeal weight increased from 4.4 mg in controls testosterone; ethynyl testosterone; acetoxypregne- to 6.7 mg following estrogen, and adrenal weights nelone. Untreated controls and those receiving increased from 21.0 to 28.7 mg. Testis weight averaged 132 mg in estrogen-treated and 639 mg sesame oil were negative. It appears that the ovulation-inducing action is in non-treated desert rats. Testis cholesterol reassociated with biological activity described as mained unchanged. The uterine response to androgen, progestin, and mineralocorticoid. Ste- estrogen in desert rats was associated with an roids classified as estrogens and glucocorticoids increase in uterine glycogen concentration. Similar results were observed in mice and rats but not were ineffective. Interestingly, the following steroids induced in hamsters and guinea pigs. (Supported by jelly secretion but no ovulation: 9-a flurohydrocor- grant 6-8630 from N.S.F.) tisone acetate; ethynyl androstenediol; vinyl an201 dro-stenediol; pregneninolone. LAURENCE LEVINE, Wayne State University. 255 Visualization of sulfhydryl groups in Vorticella convallariu. (15 min.) HOMER B. LATIMER and PAUL B. SAWIN, University of Kansas and Roscoe B. Jackson MeVorticellid sulfhydryl (SH) groups were visualmorial Laboratory. Variation in shape and posi- ized cytochemically by application of the sensitive tion of some of the viscera in the rabbit. and reportedly specific DDD (2,2'-dihydroxy-6,6'dinapthyl disulfide) reaction (Barnett and SeligVariations in position and in shape of some of the organs were observed and recorded during the man, Science, 116: 323-327, 1952). The availability of SH groups for reaction with dissections of 100 race X and 65 race I11 rabbits from the Roscoe B. Jackson Memorial Laboratory. DDD in various cell structures was dependent All of these rabbits were healthy adult specimens. upon fixative employed. Brief fixation in SchauThe lobes of the thyroid were connected by a dinn's permitted staining of SH in longitudinal thin isthmus, of varying width, in 19% of race X myonemes of the head but left most of the strucand in 28% of race 111. A few appeared to con- tures in the stalk unstained. Neutral buffered formalin fixation led to insist solely of the connective tissue capsule of the tense coloration i n both stalk and head. In the gland. Small accessory spleens were found in 12% of stalk, spasmoneme stained for SH while spasrace I11 and 22% of race X. These were located moneme canal and stalk sheath were negative. A in the supporting mesenteries or on adjacent sur- delicate helix (alpha) which coils just beneath the outer boundary of the spasmoneme canal, faces of the pancreas. Every right kidney in the 165 rabbits was more showed high SH concentration. Heads were incephalad in position than the left, varying from tensely colored, bore cilia which showed positive 25% to 125%. There were no sigrdicant sex nor reaction, but displayed no internal structure beracial differences in the relative positions of the cause they shriveled. The use of neutral buffered formol-saline prekidneys. Only three accessory suprarenals were found in vented collapse of heads but generally decreased the 165 rabbits, two in race X and one in race SH stain. However, reactivity was recovered by 111, and all in female rabbits. The right supra- treatment with thioglycollic acid (TGA). Thus renals were rather constant in position, just dor- alpha helix became more strongly positive than ABSTRACTS the spasmoneme. TGA also opened the SH of still another helix (beta) which winds around the outside of the stalk sheath. Both beta helix and longitudinal myonemes were previously shown to be loci of ATPase (Levine, Science, 131: 1377, 1960). (Supported by grant G-6457 from N.S.F.) 256 ERNEST, L. LIBBY and PERRY W. GILBERT, Marineland Research Laboratory and Cornell University. Reproduction in the clear-nosed skate, Raja eglanteria. Clear-nosed skates, Raja eglanteria, are readily maintained, occasionally mate and lay their eggs i n laboratory tanks. Mating, observed on three occasions, lasts for more than two hours; male and female repose, ventral surface down, on the bottom of the tank. The male bites the caudal margin of the female's pectoral, bends his tail 75" beneath hers and inserts one clasper, flexed medially SOa, into her cloaca and oviduct. Spines on the upper anterior surface of the male's pectora assist in holding the female. A functional ovary is present on each side and the paired oviducts have a common ostium. Eggs are usually laid in pairs; 18 days may intervene between the first and second pair. Successive pairs emerge 12, 8, 6, and finally 4 days apart. Subsequently the 4-day cycle is maintained. In Florida, eggs are laid from February through July and a single female may lay up to 66 eggs. Eggs fail to develop in water warmer than 24°C. At Marineland, Florida, it takes 9 weeks for the embryo to develop and hatch. At 20 days slits appear in the 4 horns of the egg case through which sea water freely enters and exists until hatching. At three weeks embryos removed from their cases will develop normally; at 5 weeks the tail tip beats rhythmically and maintains a current of sea water through the apertures of the case. The yolk sac is completely resorbed at 9 weeks when the embryo emerges, pectorals rolled dorsally, through the end of the case. (This investigation was conducted at the Marineland Research Laboratory, Marineland, Florida, and was aided by a grant from N.S.F.) 257 W. GARDNER LYNN and HENRY E. WACHOWSKI, Catholic University of America. Histological study of the thyroid and pituitary in the minnow Gambusiu after exposure to high temperature and treatment with thiourea. Fish maintained at 15°C for two weeks and then transferred for 24 hours to specially adapted Aminco high temperature baths accurate to 0.1"C withstood a temperature of 35.5"C before 50% mortality occurred. Treatment by immersion i n 0.05% thiourea for three weeks at room temperature and two weeks at 15°C did not significantly alter high temperature tolerance, although the thyroid, upon histological examination, did show heightened follicular epithelium and increase i n number and extent of follicles. The pituitaries were examined histologically after staining by the Elftmann aldehyde-fuchsin technique and the P aget aldehyde-thionin PAS technique. Evidence of increased neurosecretory activity in thioureatreated specimens suggested an involvement of 365 the salt balance mechanism rather than the thyroid in resistance to high temperature. Preliminary experiments involving exposure of thioureatmated fish to high temperatures in a 1% salt solution indicate a significantly higher temperature tolerance over control animals. Further work investigating the involvement of the pituitary rather than the thyroid i n high temperature tolerance in Gambusiu is now in progress. (Supported by grant A-2921 from the U.S.P.H.S.) 108 CHARLES F. LYTLE, THOMAS ELSDALE and CLARENCE M. FLATEN, Indiana University and Tulane University. Time-lapse studies of amphibian blastomeres i n culture. (Motion picture, 15 min.) Single cells and pairs of recently divided cells taken from early Rana pipiens blastulae exhibit characteristic differences in their rates of division and surface properties when grown in various media (Elsdale and Lytle, Anat. Rec., 137: 352, 1960). Time-lapse motion pictures have been taken of cells cultured i n "conditioned medium" obtained from the disaggregation of 2-3 blastulae in 10 ml of Ca++ -Mg++ -free saline (Steinberg solution), Ca++- and Mg++ -free saline alone, 3.0% horse serum i n Ca++- and Mg++- free saline, and in 0.5% bovine serum albumin in Ca++- and Mg++- free saline. The behavior of cells grown in these different media and certain abnormalities of cells in specific media will be illustrated and discussed. (This research was supported by grant RG-5850 from the U.S.P.H.S. and grant 6-4284 from N.S.F.) 67 FRANCES V. McCANN, Dartmouth Medical School. Comparative electrophysiology of fibrillar muscle. (15 min.) Flight muscle that is morphologically fibrillar and functionally asynchronous in insects of the orders Diptera and Hymenoptera, compared with Coleoptera and Hemiptera exhibit fundamental differences i n electrical activity. Fly and wasp single fibers respond to a single stimulus with an all-or-none, uniformly rising, in most cases overshooting action potential. Beetles respond with a variety of potentials, some like the type mentioned above, and others which summate and facilitate. Some of these latter responses vary with time in a cyclic manner, and some are altered by the intensity of the stimulus. Further differences are revealed by exposure to ether and carbon dioxide. In the wasp and fly ether produces a neuromuscular block, while carbon dioxide rapidly depolarizes the muscle fiber membrane. The electrical responses of bettle muscle are somewhat affected, but only by massive doses. Since electrical properties are correlated with the initial stages of the excitable process as initiated through the motor nerves, mechanical conditions in the muscle membrane, e.g., length, may. also contribute to muscle activation by effects OR permeability or on the initiation of coupling processes. One might, therefore, expect some correlation between various aspects of excitation phenomena and mechanical properties. 366 AMERICAN SOCIETY O F ZOOLOGISTS Evidence will be presented to show that the degree of activation of beetle muscle is determined not only by the stimulus, but also by the length at which the stimulated muscle is held. Conceivably this effect could be mediated through the excitation mechanism. Whether the electrical and mechanical properties of beetle muscle are related in this way or not, there is as yet no evidence that these unique qualities are found in fibriUar muscle of other insect groups. (Supported by Fellowship 5291 from the National Heart Institute of the N.I.H.) 152 ROBERT C. McCLURE, University of Missouri School of Veterinary Medicine. Occurrence of the zygomatic groove and canal in the sphenoid bone of the dog skull (Canis familiaris). (12 min.) A survey of a random collection of 145 dog skulls showed that 66 (45.5% ) of the skulls presented no groove or canal; 30 (20.6%) had grooves on both sides, and 20 (13.8% ) had canals on both sides; 15 (10.3% ) had a groove on one side and a canal on the opposite side; 10 (6.9%) presented a groove on one side and nothing on the opposite side, and 4 (1.8%) had a canal on one side and nothing on the opposite side. Of the total sides of skulls examined (290), 146 (50.3%) showed no indication of a groove or canal, 85 (29.3%) had a groove, and 59 (20.3% ) had a canal. When present, the groove was located in the dorsolateral quadrant of the alar canal and varied from a shallow furrow to a deep groove which was almost closed to form a canal. The zygomatic canal when present had its caudal opening in the dorsal wall of the alar canal rostral to the round foramen.The rostral opening of the zygomatic canal was located dorsal to the rostral opening of the alar canal. The only structure found occupying the zygomatic groove or canal was a branch of the maxillary nerve (which is described in the thesis). No correlation between occurrence of the groove or canal and age or head type was noted. (From an appendix to a thesis to be submitted to the Graduate Faculty, Cornell University, for the degree of Doctor of Philosophy.) 258 L. Z. McFARLAND, University of California, Davis. Salt excretion from the nasal glands from various species of the Pelicaniformes. The nasal glands of the Pelicaniformes are located within the orbital cavity, in contrast to the supraorbital location in the majority of other marine birds. Despite this difference in anatomical location, these glands are capable of excreting a hypertonic salt solution. Functional “salt glands” were demonstrated in 11 individuals representing 8 species of the Pelicaniformes maintained i n captivity at the San Diego Zoological Gardens. Each bird was subjected to an oral salt load consisting of 1-5 grams of NaCl according to its size, and the nasal fluid was collected and analyzed for Na, K, and C1 using standard clinical procedures. The average electrolyte concentrations found for the various species are: gannet (SuEa bassana), 650 meq Na/l, 20 meq K/1, 724 meq Cl/l; blue-footed boobie (Sula nebouxii), 980 meq Na/l, 16 meq K/1, 1210 meq Cl/l; red-footed boobie (Sula sula), 757 rneq Na/l, 19 meq K/1, 842 meq Cl/l; blue-faced boobie (Sula dactylatra), 684 meq Na/l, 17 meq K/1, 794 meq Cl/l; crested pelican (Pelicanus crispus), 734 meq Na/l, 24 meq K/1, 822 meq Cl/1; flightless cormorant (Nannopterum harrisi), 600 rneq Na/l, 14 meq K/1, 659 meq Cl/1; little pied cormorant (Microcarbo melanoleucus), 384 meq Na/l, 12 meq K/1, 528 meq Cl/l; and frigate bird (Fregata minor palmerstoni), 768 meq Na/l, 22 meq K/1, 889 meq C1/1. (Supported in part by the Biological Research Institute of the Zoological Society of San Diego.) 259 L. 2. McFARLAND, University of California, Davis. Salt excretion from the nasal glands of captive penguins. During July, 1959 and 1960, the nasal fluids from 14 individuals comprising 6 species of captive penguins was collected a t the San Diego Zoological Gardens. It was the normal practice to supplement all of the captive penguins with salt, each bird receiving from 1-6 gm of sodium chloride daily according to its size. Usually within 15-30 minutes following the ingestion of the fish in which salt tablets were embedded, drops of clear nasal fluid began dripping from the tips of their beaks. The birds frequently shook their heads to dislodge the drops. The nasal fluid was analyzed for sodium, potassium, and chloride concentrations by standard clinical procedures. The mean electrolyte concentrations 2 standard error for all samples from the penguins examined was 604f38 rneq Na/l, 16-C 1 meq K/1, and 688 23 meq C1/1. The individual species had average electrolyte concentrations of Na, K, and C1, expressed as meq/l, as follows: Aptenodytes forsteri, 604, 16, 688; Aptenodytes patagenicus, 477, 14, 594; Eudypturia minor, 591, 17, 749; Pygoscelia adeliae, 597, 17,677;Pygoscelis papua, 708, 18, 731; and Sphenisczis mendiculus, 660, 17, 690. Based on the data, all of the captive penguins examined still possessed functional nasal glands. (Supported in part by the Biological Research Institute of the Zoological Society of San Diego.) 260 L. 2. McFARLAND and M. T. CLEGG, University of California, Davis. Sexual behavior in rams and the effects of hypothalamic lesions. The sexual behavior of 32 rams was expressed as a percentage of the number of typical signs exhibited toward either estrous or anestrous ewes. Five behavioral signs were considered typical for rams of excellent libido, viz., sniffing the vulva, sniffing voided urine, curling the upper lip, uttering guttural sounds and making licking movements with the tongue. The sexual behavior of 16 rams checked with a band of anestrous ewes during the Spring of 1960 averaged 30% less than that of 16 other rams checked with estrous ewes during the Summer and Fall of 1959. It appeared that rams had a reduced sexual behavior pattern which coincided with the anestrous period of the ewe. Hypothalamic lesions involving the tuberal region resulted in a decreased sexual * ABSTRACTS behavior varying from 1 1 4 8 % below their preoperative values. However, this decrease could not be separated from hormonal influences, since destruction of similar hypothalamic areas resulted in testicular atrophy and/or altered pituitary gonadotrophin content. (From a thesis of the senior author submitted in partial satisfaction of the requirements for the degree of Doctor of Philosophy. Supported in part by grant C-3685 from the U.S.P.H.S.) 140 THOMAS E. McGILL, Williams College. Sexual behavior in inbred strains of mice. (Motion picture, 15 min.) The sexual behavior of 5 inbred strains of mice (Mus musculus) was studied. The sexual behavior of the mouse was found to differ from that of other laboratory rodents such as the rat, hamster and guinea pig. A system of scoring for more than 20 parameters of sexual behavior was developed. Significant strain differences for several behavioral measures, including time required to achieve ejaculation, were discovered. The results are discussed in terms of their importance for the comparative study of sexual behavior. The results also provide the basis for a genetic analysis of certain behavioral measures, as well as posing interesting questions concerning the physiological control of sexual behavior. The movie shows the pattern of sexual behavior in the mouse and also illustrates some strain differences. (This investigation was supported by Postdoctoral Fellowship MF-9688 from the U.S.P.H.S. The author is grateful to Prof. Frank A. Beach, University of California, for his guidance during the course of this investigation. ) 31 M. NEIL MACINTYRE, Western Reserve University School of Medicine. The biologic activity of the inductors of fetal gonadal differentiation in the rat. (15 min.) In testing, in the rat, the application of WitschTs cprtico-medullary induction theory of embryonic amphibian gonadal differentiation, it has been demonstrated (Macintyre, ’56) that when heterosexual pairs of 16-day fetal rat gonads are transplanted to a subcapsular site in the kidneys of castrated adult rat hosts the testis (representing a tissue of known medullary constitution) developed normally in every case, whereas the ovary ( a tissue of cortical constitution) was always inhibited in its development or transformed into a testis-like tissue. Additional studies (Macintyre, Baker and Wykoff, ’59) showed that with the proper age difference an older ovary will inhibit the differentiation of a younger fetal testis. These experiments indicate that the fetal gonadal cortex and medulla are capable of elaborating inductor substances which direct the differentiation of the gonad. In an effort to elucidate the nature of these morphogenic substances, studies have been undertaken to test their time of elaboration, potency and range of effectiveness. Transplants of 16day heterosexual gonadal pairs with various distances separating the members showed that as the 367 distance between testis and ovary is increased, the effect of the testis on the ovary decreases indicating that the inductor produced by the testis is effective over short distances only. Other experiments in which up to 4 ovaries have been transplanted in contact with a single fetal testis of the same age (16 days) resulted in the inhibition of all ovaries by the testis and indicate that the difference between the morphogenic substances from ovary and testis is probably one of time of elaboration rather than one of relative potency. 119 MALCOLM C. McKENNA, American Museum of Natural History. The shoulder girdle of the mammalian subclass Allotheria. (15 min.) The shoulder girdles of the mammalian subclasses Theria and Prototheria are widely different. That of the extinct subclass Allotheria has been known from a poorly preserved scrap of scapula of the Mongolian Cretaceous multituberculate Djadochtathetium. The disputed scapula and ‘Tnterclavicle” from the late Cretaceous Lance formation named Camptomus by 0. C. Marsh (1889) and referred to the Allotheria are reidentified as a therian scapula and probably an allotherian omosternal fragment, respectively. The astragalus and calcaneum referred by Marsh to Camptomus are allotherian. Two isolated scapulae have been recovered from the American late Cretaceous which in general conform to the structure of the Djadochtatherium scapula. The coracoid is fused to the scapula and the scapular spine everted as in Theria. The supraspinous fossa occurs on the medial surface of the scapula as in the Prototheria, not directly anterior to the everted spine. The subscapular fossa is confined to the posterior part of the bone. The tricipital ridge forms the glenoid border. The allotherian scapula, therefore, combines certain features of the Prototheria and Theria. The allotherian stance was apparently little advanced over that of the cynodonts, but the everted scapular spine is more an indication of therian than of prototherian affinity. 26 1 SAMUEL R. MAGRUDER, Tufts University School of Medicine. Innervation of the tongue musculature of Eptesicus fuscus. Tissue from 5 adult bats (Eptesicus fuscus) was prepared by the Nonidez method for staining nerves. The tongue muscles appeared more profusely innervated than other muscles examined from the same specimens. This may be partially due to a relative telescoping of these nerves compared to those innervating larger muscles. On the basis of dissections plus serial sections of the tongue it was tentatively concluded that the motor supply to the bat’s tongue was entirely via the hypoglossal nerve. The preterminal efferent nerve fibers divided abruptly at the motor end plate into three to 6 terminal twigs which appear to clasp the muscle fiber. Some of these terminals 368 AMERICAN SOCIETY O F ZOOLOGISTS end as tapered points. But more than 70% end as rings, loops, solid expansions or neurofibrillar nets. These observations are not in agreement with the recent statement (Coers and Woolf, ’59) that all motor endings, after silver staining, show only tapered twigs. Motor end plates of the bat’s tongue are larger and more complex than comparable endings in pectoral intercostal and psoas muscles from the same animals. There is no correlation between the morphology of the motor end plates and the size of the muscle fibers. It was not determined if the motor ending was located at the midpoint of the muscle fiber. An autonomic ganglion, consisting of three to 10 cells, was found bilaterally, i n the posterior third of the tongue. It was associated with a small nerve tentatively identified as a branch of the trigeminal. No muscle spindles nor any other afferent endings associated with the musculature have been seen. Very few branching muscle fibers were observed; their innervation does not differ from unbranched muscle fibers. 262 LUBOW A. MARGOLENA, Animal Husbandry Division, Agricultural Research Service, United States Department of Agriculture. Season and comparative activity of wool follicles. Forty Rambouillet rams from the genetically stabilized line at the United States Sheep Experiment Station, Dubois, Idaho, were divided at random into 4 groups of 10 rams each. One group remained in Idaho, while the other groups were sent to University Park, New Mexico, Tifton, Georgia, and Beltsville, Maryland, respectively. Of each group of 10 rams, 5 were maintained under normal management practices and 5 were kept in barns and individually fed a ration of 5.4 pounds (90% dry matter basis) of alfalfa pellets per day. All pellets used at the 4 locations were made from a common source in Idaho. Microscopic examinations of histologic preparations of early March, late April, early May and June, and mid-October biopsies of the Rambouillet skins revealed no seasonal shedding. The depth of follicular penetration of the follicles in the dermis showed considerable uniformity, the maxima ranging from 3.75 to 4.40 mm. Above measurements corroborate the general impression that fine woolled sheep do not undergo seasonal molt or molts, which would necessarily be associated with spectacular upward migrations of all or certain types of follicles. Irrespective of location, the wool follicles of individually fed rams showed slightly deeper penetration as compared to the pasture kept members of their groups; this seems worth noting as the same barn kept animals produced also heavier fleeces. Mitotic counts in the wool matrices of the Idaho and Georgia skins (300 mitoses were covered per biopsy), tend to indicate that cell divisions directly responsible for the growth of the wool fiber tend to slow down during the colder months to about 72% of that found in early summer. 70 JEAN M. MARSHALL, Harvard Medical School. Relationship between transmembrane potentials and contractile tension in uterine smooth muscle. (15 min.) Simultaneous recordings of transmembrane potentials and contractile tension were obtained from isolated uteri of rats. The animals were ovariectomized and divided into three groups: untreated controls, estrogen-treated (6 pg estradiol benzoate daily for 5 days), estrogen-progesterone treated (6 pg estradiol for three days, then 1.6 pg estradiol plus 12 mg progesterone for 5 days). The membrane potentials of the untreated control uteri were quite low, mean 35.2 mv, and these muscles were quiescent. Estrogen raised the membrane potential to a level (57.6 mv mean) sufficient to produce trains of action potentials which initiated contractions. These rhythmic contractions were always preceded and accompanied by action potentials, the frequency of which increased as the tension developed, then diminished and ceased altogether as the tension subsided. In small strips of uterus, it was possible to note that the magnitude of the developed tension was related directly to the frequency of action potential discharge. Progesterone increased the membrane potential to a level (63.8 mv mean) where areas of conduction block occurred. The contractions of these muscles were sporadic and irregular. Furthermore, there was no consistent relationship between the discharge of action potentials and contraction. Discharges in a given fiber either preceded a contraction, or occurred only after tension had developed, or were entirely absent during a contraction. 263 G. M. MATEYKO and M. J. KOPAC, New York University. Cytological studies on renal cultures of Rana pipiens. A cytological and cytochemical study of normal and adenocarcinomatous frog renal tissue in tissue culture was made. In a medium consisting of Gey’s solution, chick embryo extract, and sterile human ascitic fluid of malignant ovarian origin, both types maintained their own individual characteristics, the malignant explants exhibiting more rapid growth and variability characteristic of neoplasia. After cultures were established, growth could be held in abeyance without renewal of medium for periods up to 4 months by storage at a temperature of 4°C. The following studies were made: phase contrast on living cultures including acrylonitrile; hypotonic, acid, and alkaline media; trypsin and RN-ase; hematoxylin and eosin; Pianese; Schleifstein; eosin and methylene blue; acetoacein-fast green; ferricyanide; methyl green-pyronin; acid hematin; brilliant cresyl blue, methylene blue, methylene violet (Bernthsen), toluidine blue 0 at controlled levels of pH; PAS; Sudan N and Sudan black B; Nile blue sulfate; nitroprusside; Millon; Sakaguchi; Schultz; and Estable and Sotelo silver nucleolonemal techniques. Control studies included the hydrolytic and enzymatic 369 ABSTRACTS sequential removal of nucleic acids, protein, lipid, carbohydrates, etc. Briefly, in contrast to normal tissue, tumor cells show the frequent occurrence of acidophilic cytoplasmic inclusions (RN-ase labile), much cytoplasmic RNA and protein, some particulate lipid birefringent in polarized light, perinucleolar phospholipid, SchSpositive droplets in the cytoplasm and diffuse PAS-positive material, and considerable amounts of nucleolar RNA, histone, basic protein, with a nucleolar structural constituent resistant under usual conditions, to the sequential action of carbohydrases, nucleases, and proteolytic agents. (Supported by grant C-4410from the U.S.P.H.S.) 264 RAOUL MICHEL MAY and JEAN-PIERRE DENLFLE, Facult6 des Sciences, University of Paris. Comparison of the direct action of ultra-violet and x-rays on the in vitro growth of nerve fibers from irradiated spinal cords of chick embryos. The thoracic and lumbo-sacral spinal cord of 7-day old chick embryos was split longitudinally into two halves, on either side of the central canal, and each half was cut into 3 4 fragments. These were placed in small sterile dishes containing 5 m l of Ringer's solution and irradiated through a cellophane membrane. One of the two identical lots served as a control, being covered over with a tin sheet in the case of exposition to ultra-violet rays, undergoing no irradiation in that of x-rays. They were then further subdivided into cubes about 1 mm3 and cultured in de Fonbrune's oil chambers at 38°C. They were photographed and cinematographed after 24 and 48 hours growth. Ultra-violet rays: 569 controls and 545 cultures stemming from fragments irradiated 7 cm below a lamp emitting 3003 A. This band has an effect on the nerve fibers: (1) it stimulates quantitatively and qualitatively their growth if they are irradiated up to 90 min.; (2) it inhibits their growth if the irradiation is prolonged beyond 90 min. The exposition during 90 min under these conditions is thus a liminary threshold between their stimulation and their degeneration. X-rays: 344 controls and 336 cultures irradiated with 3400 and 3825 r (70 kv). These strong doses are necessary in order to bring about degeneration of the nerve fibers more rapidly than in controls. Besides, minimal and medium growths predominate in the case of fibers from irradiated fragments, while optimal growth does so in that of controls. While a certain dosage of ultra-violet irradiation has thus a stimulating action on the growth of nerve fibers, this does not occur with x-ray irradiation. 171 DONALD M. MAYNARD, University of Michigan. Forms of activity within the neuropile of the spiny lobster. (15 min.) Intracellular recordings were obtained from the semi-isolated, perfused, and desheathed cerebral ganglia of the spiny lobster (Panulirus argus). In most cases reported here, the electrode tip was presumably lodged in fibers contributing to the deutocerebral neuropile at the base of the antennular nerve. "Spontaneous" activity in cerebral elements took three forms: (1) spike discharges arising from slowly developing generator potentials; (2) spike discharges arising from and initiated by a background of post-synaptic potentials; (3) subthreshold post-synaptic discharge only, usually composed of several potentials differing in amplitude. Both depolarizing (epsp) and hyperpolarizing (ipsp) post-synaptic potentials were often present. Such continuous discharges frequently could be accelerated or inhibited by illumination of the eye, by stimulation of the antennular nerve, or by both. In several instances, 2-3 spikes of varying amplitude and discharge frequency apparently recorded from one unit suggested independent sites of impulse origin along the neuron processes. Stimulation of rapidly conducting (5-15 m/ sec. at 28'C) afferent fibers in the antennular nerve caused post-synaptic potentials in internuncial or motor units. A single epsp was characteristically insufficient to initiate a propagated, post-synaptic response. Spatial summation was prominent, and all elements examined apparently received input from several antennular fibers. Pure temporal summation was present, but in these experiments usually seemed associated with defacilitation of the epsp. Facilitation was rare. Nevertheless, the summed post-synaptic response to a single massive stimulus of the antennular nerve frequently lasted several tenths of a second. In the absence of repetitive discharge in the initial input, this suggests some re-excitation or cascading circuit within the neuropile. Antennular nerve stimulation occasionally produced ipsp. These tended to become depolarizing as the membrane potential increased. As with the epsp, ipsp showed evidence of spatial summation with increasing stimulus strengths. Some elements showed both epsp and ipsp in response to massive, indiscriminate stimulation of the antennular nerve. (Aided by a Summer Faculty Research Fellowship and Rackham Research Grant 497, The University of Michigan.) 124 EDITH A. MAYNARD, University of Michigan. Cholinesterases in two autonomic ganglia of the lobster, Homarus americanus. A histochemical study of cholinesterases in lobster cardiac and ventricular (stomatogastric) ganglia was made, using the thiocholine method of Koelle ('51). Material subjected to substrates (acetylthiocholine or butyrylthiocholine) was in the form of unfixed, frozen sections, or freshly dissected whole ganglia. After completion of the histochemical reaction the intact ganglia were preserved as whole mounts or were dehydrated, embedded in paraffin, and sectioned. Both ganglia are located within the circuratory system and both contain motor neurons, those of the cardiac ganglion innervating heart muscle and those of the ventricular ganglion going to gut musculature. The cholinesterase reactions are very dissimilar in the two ganglia. The ventricular ganglion, like the central nervous system 3 70 AMERICAN SOCIETY OF ZOOLOGISTS (Maynard and Maynard, ’60), contains large amounts of cholinesterase, located principally in sheath cells around nerve cell bodies and in neuropile; the neuron somata may have a moderate reaction in the periphery of the cytoplasm but in general nerve cells and their larger processes contain little enzyme. The cardiac ganglion, in contrast, has only a very small amount of cholinesterase, contained in sheath cells around neuron somata and processes. Complete inhibition of the reaction with acetylthiocholine was obtained in cardiac ganglia in the presence of M eserine sufate, M di-isopropylfluorophosphate (DFP), or M B.W. 2e4C5lj dibromide (BW), and in ventricular ganglia with lO-5M eserine sulfate, 10-4M DFP, or lO-3M BW. Complete inhibition of the reaction with butyrylthiocholine occurred in M eserine sulfate, cardiac ganglia with 10-BM DFP, or lO-5M BW, and in ventricular M DFP, ganglia with 10-5 M eserine sulfate, or 10-SM BW. (Supported by U.S.P.H.S. grant M-1379 to R. W. Gerard. DFP was obtained from Dr. B. J. Jandorf, the Army Chemical Center, Maryland, and BW from Dr. E. de Beer, the Wellcome Research Laboratories, Burroughs Wellcome and Co., Tuckahoe, New York.) 212 206 ROGER MILKMAN, Syracuse University. Rapid temperature adaptation in Drosophila metanogaster pupae. (15 min.) Twenty-four hours (at 23‘C) after puparium formation, Drosophila melanogaster pupae are maximally sensitive to disturbance of posterior crossvein formation by exposure to temperatures in the range 39.5-41.5’C. Over this range, the Q1 for this effect is uniformly 2.3. Longer exposures result in death. Prior exposure at 37.5“C for as little as 5 minutes results in increased resistance both to crossvein disturbance and to death. The degree of adaptation is a function of duration at 37.5’ and of the interval between treatment at 37.5” and treatment at the higher temperature. The adaptation at 37.5’ is differential, since any subsequent exposures to temperatures between 39.5” and 41.5‘ which are insufficient to kill the animals will produce no crossvein defects. This contrasts with the apparently non-differential adaptation resulting from aging the pupae at 28’ rather than at 23‘ from the time of puparium formation to the time of treatment. Possible mechanisms and applications are discussed. (Supported by grant 6-9785 from N.S.F.) 265 ALBERT0 MONROY and LETIZIA VITTORELLI, tural variations and composition of the nuclear University of Palermo, Italy. A study of the envelope. (15 min.) cell fluid proteins of the egg and developmental stages of Paracentrotus Zividus. Nuclear envelopes from nearly mature eggs of Rana pipiens were isolated in KC1 solutions, Cell fluid proteins (proteins remaining in solutreated with enzymes, and fixed in various ways. tion in 0.5M sucrose at pH 6.4 after one hour Whole mounts were air dried for electron micros- centrifugation at 105,000 G and dialysis to reCOPY. move low molecular components) of unfertiThe envelope is covered with the usual annu- lized eggs and developmental stages of Pamcenlated “pores” which can be seen after OsOa, trotus lividus have been studied by zone electroKMn04, and 10% formalin fixations. Differen- phoresis in starch (borate buffer at p1-I 8.6). tial solubilities and enzyme digestions indicate Under these conditions three main components that the ‘‘pore” is not a hole. A “pore” diaphragm can be recognized, all of them with anodic mimaterial or membrane, at least partially protein, gration. The fastest component, a, has been is of remarkably constant density and must be identified as ribonucleic acid. The intermediate considered part of the nuclear envelope. The and largest one bears indications of being made surrounding annulus is chemically and structur- up of at least two incompletely separated comally of different nature than the diaphragm, sur- ponents, b and b’. The former is a nucleoprotein, rounding and partially filling the diaphragmed the latter exhibits a typical protein spectrum. “pore.” Neither diaphragm nor annulus contains Also the slowest component, c, has a protein digestable RNA but both, along with the bilami- spectrum. Estimates of the areas of the three nar membrane, are destroyed by trypsin. main components indicate a significant increase In addition there are numerous differentiated of c during cleavage stages; from the morula areas ranging from less than one to three microns stage on the increase is not statistically signifiin diameter. In these, the two elements of the bi- cant. Analyses carried out on cell fluid proteins laminar membrane are separated, one of them from embryos raised in the presence oE W-methballooning out from the other. The usual annulated ionine show a lively uptake in b,b’ and c at all “pores” are here replaced by dense granular zones stages of development. The uptake in c is, howcontaining “pore”-like circular structures on one ever, the highest during the cleavage stages; of the membranous elements only. The dense from then on it is stronger in b’. No activity at material does not contain digestable RNA but is all has been found in a. These results are sugdestroyed by trypsin. gestive of a synthesis of at least one protein alOther dense, granular areas containing “pores” ready during cleavage. O n the other hand, owing in close hexagonal packing adhere to the surface to the incomplete separation of b and b’, it has of the envelope. They contain n o digestable RNA not been possible to decide whether the uptake jn and their “pores” are not in register with the these components is due to a synthesis or to a underlying “pores” of the envelope. (Supported turnover. (Supported by grant RG-6211 from the U.S.P.H.S.) by U.S.P.H.S. Training Grant 2G-216(C2).) R. W. MERRIAM, Columbia University. Struc- ABSTRACTS 134 FLORENCE MOOG, Washington University. Influence of thyroid hormone on the functional differentiation of the duodenum in the chick embryo. (15 min.) Incubating eggs were injected with 3.8 mg of thiourea (TU) at 11 days. As others have previously found, such treatment causes enlargement of the thyroid glands and severely slows the rate of development. In TU-retarded embryos the accumulation of duodenal alkaline phosphatase, which normally proceeds very rapidly between 17 and 21 days, lags 4-5 days behind that i n the controls. Duodenal phosphatase activity does not rise above the normal 19-day level, even as late as a week after the controls have hatched. The naturally-occurring pre-hatching increase in general protein concentration in the duodenum fails entirely. Differentiation of the intestinal epithelium, examined by histological and histochemical techniques, is inhibited in parallel with the retardation of phosphatase development. Although exogenous corticoids ordinarly accelerate intestinal differentiation, including the synthesis of phosphatase, the action of cortisone acetate (1 mg injected at 14 days) is completely blocked in embryos previously treated with TU. The inhibitory effects of TU on the duodenum are fully reversed by 1-thyroxine (1.5 pg injected at 13 and at 15 davs). If TU-treated embryos are given 1-thyroxine at 13 and 15 days and cortisone acetate at 14 days, the accumulation of phosphatase is accelerated to the same degree as in control chicks given cortisone alone. Evidently the prehatching differentation of the chick duodenum, whether under normal conditions or under the influence of exogenous corticoid, requires the presence of thyroid hormone. (Supported by grant RG-3937 from the U.S.P.H.S.) 42 A. ULRIC MOORE and MARVIN AMSTEY, Cornell University. Animal hypnosis (tonic immobility) considered as a parameter of behavior in distinguishing between a group of normal and abnormal (experimental) lambs and kids. (15 min.) A number of species of both birds and mammals are known to yield to experimental tonic immobility or “animal hypnosis.” The phenomenon is also widely encountered in the natural state, where it commonly has been interpreted by behaviorists as an innate mechanism for evading predators by shamming death after capture. A group of 15 experimental animals (lambs and kids) whose maternal bond had previously been modified through forced adoption by interchanging their mothers postpartum were a11 found at 6 months of age to be unsusceptible to hypnosis, whereas all control animals were readily immobilized. The animals were selected in intergroup random order and the “hypnotist” was uninformed as to respective identities. Two sets of tests were run and found to yield consistent data. Other functional anomalies noted in the adoption syndrome include : immature physical development, hyper- or hypo-activity under experimental stress, and poor differentiation between the foster mother and other females in the Aock. 371 An interpretation of these data is made in terms of Pavlov’s theory that sleep and hypnosis are related phenomena in animals and an hypothesis is presented regarding the relationship to sleep of the neonate quiescent or “resting phase” observed during this early period of development. Tonic immobility in adult animals is regarded as an energy function of the nervous system called into play by the disruption of flight capacity. A similar function for protecting the nervous system from noxious amounts of stimulation is tentatively conceived of as existing in the neonate animal. (This work was done at the Behavior Farm Laboratory and was supported in part by a grant from the Josiah Macy, Jr. Foundation.) 141 LARRY L. MORGENSTERN, University of Kansas. Changes in sexual behavior in spayed female guinea pigs following anterior hypothalamic lesions. (Introduced by William C. Young) (15 min.) Seven adult females from strain 13 and 8 from genetically heterogeneous stock T were used. Electrolytic lesions were placed stereotaxically in the anterioventral hypothalamus. Four tests for mounting behavior and receptivity were given preoperatively and 5 postoperatively. On each test estrus was induced by injection of estradiol followed 36 hours later with progesterone; vigor of lordosis was measured 12 times at hourly intervals. Maximum vigor of lordosis declined from means of 24.5 and 18.4 seconds preoperatively to 9.7 and 4.1 postoperatively in strain 13 and stock T respectively. Postoperatively, vigor of lordosis was lower on every measurement. Mounting was eliminated in 6 animals, lordosis in only three. Moreover, mean frequency declined from 12.5 and 8.1 preoperatively to 3.9 and 0.5 postoperatively for strain 13 and stock T respectively. Preoperatively mounting was observed in 70 of 89 determinations (77.8% ) postoperatively, in 28 of 104 (26.9% ). The lesions produced a continuous series of reductions in frequency of mounting and vigor of lordosis. Postoperatively, three animals showed complete absence of sexual behavior, 9 showed degrees of loss, and three no change. Histological study failed to show conclusive similarities within groups or differences between groups as to locus or size of lesion. The findings suggest a complex participation of the hypothalamus i n the determination of degrees of expression of the components of sexual behavior in contrast to the concept of an all-or-none sexual “center.” (Supported in part by grant M-504 from the U.S.P.H.S. The author was a recipient of a U.S.P.H.S. Traineeship to the Department of Psychiatry.) 266 JAMES M. MOULTON, Bowdoin College. The acoustical anatomy of teleost fishes. The notable variety in teleost fishes is reflected no less in their acoustical anatomy than in other aspects of their morphology. Special adaptations facilitating hearing and sound production bear extensive review. 372 AMERICAN SOCIETY O F ZOOLOGISTS 179 WILLIAM B. MUCHMORE, University of Rochester. Muscle proteins in early amphibian embryos. (15 min.) There has been considerable controversy recently concerning the first appearance of muscle proteins in the development of vertebrate embryos. The following data indicate that actomyosin-like antigens do occur in embryos of the salamander well before the development of crossstriated muscle fibers. It has not proved possible to isolate pure myosin from amphibian muscle. Therefore, antibodies were prepared in rabbits against actomyosin extracted from the body muscles of Necturus maculosus with Guba-Straub solution. The resulting sera showed positive precipitin reactions with homologous antigen at dilutions of at least 1:1024. Some of the sera were absorbed with the vitellin fraction of the yolk proteins of ovarian eggs, which gave a positive precipitin reaction. These sera were then shown to be specific for the muscle proteins. Embryos of Ambystoma macuZatum at various stages were homogenized in Guba-Straub solution, and the cleared extract used in agar diffusion and microprecipitin tests 50 with the absorbed sera. Positive results were obFRANK MOYER, Johns Hopk!ns University. tained with the Ouchterlony technique using exSome effects of pigment mutabons on the fine tracts of Harrison’s stage 39 or later. With the structure of mouse melanin granules. (Intro- microprecipitin test (in capillary tubes) positive duced by C. L. Markert) (15 rnin.) reactions were obtained with embryos as early as Recently electron microscopy has revealed that stage 23. This result is in general agreement with mouse melanin granules develop through an or- the finding by Ogawa (Nature, 182: 1312, 1958) derly sequence of 4 stages, each with its own that myosin-like antigen first appears in Triturus characteristic fine structure, the final stage cor- pyrrhogaster embryos at stage 24 and actin-like responding to the mature granule. Furthermore, antigen at stage 19. The exact nature of the antiseveral pigment mutations result in subtle changes genic molecule responsible for these early rein the details of this developmental sequence and actions and its localization in the embryo are the these changes can be correlated with observed object of continuing investigation. (Supported phenotypic effects (Moyer, Anat. Rec., 134: 612, by grant G-5540 from N.S.F.) 1959, and 136: 248, 1960). Pigment mutations which grossly alter granule morphology may be 135 expected to alter the fine structure of the developPHILIP F. MULVEY, JR., A. C. BALLAS 2nd D. ing granule to a greater degree, and in ways which W. SLINGERLAND, Veterans Administration may provide clues to the nature of the primary Hospital, Boston. The in vitro stimulation of gene product involved. Accordingly, electron mi(15 thyroidal activity by propylthiouracil. croscope observations have been made of the rnin.) retinal pigmented epithelium of embryos and In vitro studies were made which indicated neonatal mice from inbred strains carrying the M) genes for pink-eyed dilution (aaBBpp) and al- that a small amount of propylthiouracil ( added to the medium increased the total uptake bino (aabbcc). The melanin granules in the pigment epi- of radioiodine by rat thyroid slices under both aerobic (206% after 30 minutes) and anaerobic thelium of pink-eyed mice are irregular in shape (162% after 300 minutes) conditions. Chromatand are smaller than those of the wild type. This morphology can be correlated with the structure ographic studies (aerobic) showed a possible inof the stage 2 granule in which the internal fibers crease in the amount not only of trapped radioiodide (110%) but also organic radioiodine are arranged in a different order than those of (132%) and a decrease in the ratio of iodide/ the wild type. In the albino mouse no mature melanin granules are formed; however unpig- organic iodinated compounds (I-/Io) (1.09 to mented “precursor granules” (stages 1 and 2) do 0.86). In addition, there was a decrease in the ratio of radiomonoidotyrosine to radiodiiodotyroform and are similar i n appearance to those of pigmented strains. Apparently the albino stage 2 sine (MIT/DIT) in the propylthiouracil treated slices (5.6 to 2.0), indicating that there was a granule is incapable of further development. This finding lends support to the theory that the stage relatively greater stimulation of organification 2 granule is the site of tyrosinase activity in pig- and conversion of MIT to DIT than iodide trapmented mice. The implications of these findings ping. Chromatographic studies (anaerobic ) also will be discussed. (Supported in part by an mdxated a possible increase in the amount of N.S.F. grant and by grants H-3141 and CF-9040, trapped radioiodide (108% ) as well as a definite increase in organic radioiodine (161%) and a U.S.P.H.S.) The teleost ear is not so thoroughly enclosed in skeletal parts as is the ear of other vertebrates, and thus, as D. R. Griffin has noted in another connection, the soft tissues provide for sound transfer between water and the sensory ear a medium much like water in its acoustical transparency. The movements of fishes in the water-Trachurus trachurus (Shiskova, E. V., Rybnoe Khoziaistvo, 34: 33-39,1958) Anchoviella choerostoma, Caranx sp., Trachinotus palometa-create considerable sound which is probably of biological sigdlcance. The hydrostatic function of the Prionotus air bladder is admirably adapted to sound production. Species-characteristic sounds are produced by the air bladder of Prionotus evolans when up to 1/3 of the gas is removed from the air bladder of fish contained at the surface. (Supported by grant G-4403 from N.S.F., by the Woods Hole Oceanographic Institution, and by the Faculty Research Fund of Bowdoin College. Part of the work was performed at WHO1 and at the Bermuda Biological Station.) ABSTRACTS decrease i n the ratio of I-& (1.64 to 1.23). Further, there was a significant increase in oxygen consumption (152% after 60 minutes) by the propylthiouracil treated slices. The results indicate a direct stimulatory effect, in uitro, by small amounts of propylthiouracil on oxygen consumption and thyroxine biosynthesis. The different reactions involved in thyroxine biosynthesis are stimulated to varying degrees. 373 These observations suggest that intraperitoneally injected Thorotrast, in addition to entering the lymphatic system, is also carried by macrophages through the surface of the mouse liver to the hepatic sinusoids. (Supported by grants CRT-5007 and (2-510 from the U.S.P.H.S.) 154 HENRY C. NATHAN, The Wellcome Research Laboratories. The use of specific pathogen-free 191 mice for tumor studies. (Introduced by Samuel Bieber) (15 min.) WILLIAM R. MURCHIE, The University of Michigan Flint College. Production of spermatoComparative studies on tumor growth were carphores by Dendrobaena samarigera Rosa 1893. ried out with Specific Pathogen Free (SPF) Swiss(12 min.) Bagg and Ha/ICR Swiss mice. Fragments of SarThe lumbricid D. samarigera shows constancy coma 180 (1-2 mm3) were implanted by means in the formation of large spermatophores associ- of a trocar in the right axillary region. Ten days ated with the male porophore. These spermato- after implantation the animals were sacrificed phores occur on the dorsal or dorso-lateral aspect and the tumors were calipered and weighed. of segments 15 and 16. Rosa (Bull. Mus. Torino, While the average tumor weights in both groups 8: 1-14, 1893) correctly assumed these structures were comparable, the SPF animals exhibited a to be produced by glandular cells of the poro- significantly narrower range of tumor sizes and weights as compared with the standard Swiss phore. Histological sections of specimens recently ob- mice. This uniform tumor growth is a desirable tained, indicate that the dorsal body wall of D. feature for experimental chemotherapy. Prelimisamarigera is actively involved in retention of nary experiments indicate no differences in the these spermatophores and further, appear to chemotherapeutic response of the tumor carried substantiate the conclusions of Ribaucourt (Bull. in the SPF mice as compared with the Ha/ICR Sci. France Belg., 35: 211-311, 1900) that, in at mice. Studies were carried out to determine the least some species of Oligochaeta, the segments producing and bearing the spermatophores are changes in the bacterial flora of SPF mice housed the same. Thus, their presence does not neces- in a common colony room. Upon receipt they sarily indicate that they have been deposited by were verified to be free of bacterial pathogens whereas the standard mice revealed subclinical a partner in copulation. titres of salmonella, streptococcus, proteus and 218 shigella. Noteworthy is the fact that SPF mice PAUL K. NAKANE, Brown University. Histologi- had smaller spleens and livers. All animals were cal observations on the effect of intraperi- housed in cages with wire mesh bottoms. Cages toneally injected Thorotrast on the surface of were changed weekly and scrubbed and boiled. the mouse liver. (Introduced by E. H. Leduc) When maintained in separate cages the animals remained pathogen free for 6 months; when (15 min.) Thorotrast combines with unknown basophilic housed in the same colony cage with standard substances in the peritoneal cavity, and accumu- mice, the SPF animals remained pathogen free for lates between the connective tissue of Glisson’s 8 weeks. The stability of this condition may allow for a wider application of this type of mouse to capsule and the mesothelium on the surfaces of the mouse liver. Lymphocytes collect inside the experimental programs. Glisson’s capsule beneath the aggregates of 214 Thorotrast. During the first day after injection, these lymphocytes are located between the hepatic R. BRUCE NICKLAS, Yale University. The cytology of Mycophila speyeri and the origin of the cells and within indentations on the surface of gall-midge chromosome cycle. (15 min.) these cells. On the second and third days this The bizarre gall-midge (Cecidomyiidae; Dipindenting process disrupts the superficial hepatic cells, and the lymphocytes move further into the tera) chromosome cycle poses many problems of liver. Macrophages loaded with Thorotrast pene- wide interest, but few are more alluring than the trate the connective tissue layer of the capsule question of the evolutionary origin of this cycle and follow the lymphocytes thus coming in con- from the more orthodox cycle of the gall-midge tact with the hepatic sinusoid. During the third ancestors. An attack on this question has been and 4th days, a new layer of connective tissue made by cytological investigation of the primitive forms between the damaged and the undamaged gall-midge, Mycophila speyeri. The chromosome cycle of Mycophila has three features also found regions of the parenchyma. Vacuole-like spaces appear beneath Glisson’s in more specialized gall-midges: a large number of capsule and among the damaged hepatic cells on chromosomes in the germ-line, chromosome elimthe second and third days. Thorotrast-laden ination from future somatic cells during early macrophages invade these spaces during the 4th cleavage, and chromosome elimination in spermatogenesis. However, sexual oogenesis lacks day. Thorotrast aggregates also accumulate on the unusual features found in other gall-midges, other surfaces of the peritoneal cavity; however, and instead there is normal chromosome pairing the process of invasion seen in the liver does not and segregation. The studies on male and female meiosis suggest that sexual progeny begin develoccur. 374 AMERICAN SOCIETY OF ZOOLOGISTS opment with fewer chromosomes than their parents possessed, and therefore a compensatory increase in chromosome number probably occurs during early cleavage i n sexual progeny. The evolutionary origin of the gall-midge chromosome cycle is considered in the light of these results. It is concluded that the essential innovation in the ancestral group was a n increase in chromosome number, possibly by polyploidy, and that chromosome elimination in cleavage and spermatogenesis made possible the perpetuation of this elevated chromosome number. Modifications of oogenesis are viewed as secondary adaptations not present in the early gall-midge stock. 27 CHARLES NORMAN, ERWIN GOLDBERG, I. D. PORTERFIELD and C. E. JOHNSON, West Virginia University. Prolonged survival of human sperm and other mammalian sperm in chemically defined media at room temperatures. (15 min.) Successful maintenance of metabolically and functionally active bovine sperm in a coconut milk diluent suggested the possibility of sustaining human sperm and other mammalian sperm in chemically definied media at room temperatures for an extended period of time. Semen collected from human donors was pooled after liquefaction. Bovine and rabbit semen were collected with an artificial vagina. The sperm were washed twice in the medium under investigation and the final volume adjusted to give an appropriate cell concentration. All media tested contained the following additives in final concentration: 31 mg% penicillin (Na), 68 mg% dihydrostreptomycin sulfate, 300 mg% sulfanilamide, 4 units mycostatin/ml and 150 units aqueous solution of sterile catalase per ml. The sperm suspensions were poured into sterile plastic vials, completely filled and stored in the dark at room temperatures (25°C & 2°C ). Initially and daily thereafter separate vials were removed, inverted several times prior to counting viable cells and measuring motility quantitatively as well as qualitatively. Tris (0.02 M) buffered maintenance medium 199 (Hyland Laboratories) gave the best survival rate for human spermatozoa. In this medium the number of viable and vigorously progressive human cells remained relatively constant for 5-6 days. Although bovine sperm survived well in medium 199, a modified White's medium achieved comparable results and is more desirable for metabolic and nutritional studies because of its simpler composition. Rabbit sperm were satisfactorily maintained in Hank's solution for 3-4 days. In all cases 0.5-1.0% egg yolk substantially enhanced sperm survival time. (Supported by grant RG-6339 from the US. P.H.S.) 175 CHARLES NORMAN, CLYDE E. JOHNSON, ERWIN GOLDBERG and I. D. PORTERFIELD, West Virginia University. A chemicalIy defined maintenance medium for bovine sperm. (Introduced by Lloyd R. Gribble) (15 min.) A chemically defined medium has been developed for the in witro maintenance of metabolically and functionally active bovine spermatozoa for more than a week at close to physiologic temperatures (25°C f 2°C). The composition of this medium is: 7.3 X lo-% M sodium citrate dihydrate, 2.7 x M glucose, 2.1 x 10-e M magnesium sulfate heptahydrate, 2.4 X 10-3 M sodium sulfate, 1.5 X 10-3 M potassium chloride, 1.3 X M potassium nitrate, and 2.3 X lo-* M monosodium phosphate. These basic ingredients dissolved in 3 x distilled water contained the following additives in final concentration: 31 mg% penicillin G (Na), 68 mg% dihydrostreptomycin sulfate, 300 mg% sulfanilamide, 4 units mycostatin/ml and 150 units catalase/ml. Survival of washed cells suspended i n this salt solution remained relatively constant for 5 days and declined approximately 25% on the 6th day. The significance of this development is that it provides a vehicle for precise environmental control enabling a more comprehensive and definitive study of cell metabolism and function. (Supported by grants RG-6339 and E-2497 from the N.I.H., U.S.P.H.S. and a grant from the N.A.A.B.) 88 RONALD R. NOVALES, BARBARA JEAN NOVALES and STEPHEN H. ZINNER, Northwestern University. Further studies on ionic factors influencing intermedin action on frog skin. (15 min.) Previous studies (Novales, '59 and Wright and Lerner, '60) have shown that sodium is required in the medium for the specific response of the melanophores of isolated frog skin to intermedin (melanocyte-stimulating hormone, MSH). Neither potassium, choline, lithium nor guanidinium ion were able to replace sodium. Further attempts have been made to find a substitute for sodium. Ammonium, hydrazinium, tetramethylammonium and tetraethylammonium Ringer all darkened skins slightly by themselves in an hour. MSH did not produce a greater darkening in the above solutions, thus none of these ions were able to replace sodium in the response. There was a 10fold reduction of the sodium content of skin kept in sodium-free media. In view of the importance of calcium in excitable systems, calcium-free Ringer with sodium citrate (6mM) has been employed. This had no darkening effect of its own. The magnitude of the response was greater in the calcium-free Ringer, since skins in this medium darkened 17% more in a high MSH concentration than with MSH in normal Ringer. Calcium-free Ringer treatment had little effect on the calcium content of skins. Experiments with oxalate and EDTA Ringer were also conducted, as well as with Ringer with 10 times the normal calcium content. The effect of replacement of Ringer chloride with bromide, sulfate or nitrate was studied. These results will be discussed in terms of the role of the above ions in melanophore physiology and cellular excitability. (Supported by grant G-9019 from N.S.F. and by the Graduate School, Northwestern University.) ABSTRACTS - 194 ROBERT E. OGREN, Dickinson College. Observations on the immature hexacanth embryo of Hymenolepis diminuta, a tapeworm of mammals. (10 min.) This undifferentiated invertebrate embryo is characterized by the presence of 6 hook-forming cells (oncoblasts) at present unknown in any other group. Each oncoblast contains a specialized hook-forming center with abundant mitochondria; here the original blade is formed. The body of the immature oncosphere is composed of medullary and cortical mesenchymal cells. A binucleate medullary cell is present near the central part of the embryo. In addition to the above, the nearly spherical embryo contains two large cells with abundant granular and filamentous mitochondria. These have been previously termed epidermal gland cells (Ogren, J. Parasitol., 45: 575-579 1959). These immature oncospheres have not developed contractile movements. Protective envelopes enclose the hexacanth. The thin transparent outer shell, ellipsiform in outline, covers a layer of large refractile globules. The future inner capsule being devolped around the oncosphere beneath the envelope of globules is indicated by the presence of thin membranes. Observations were made by phase microscopy and the usual histological technique. (Supported by grant 6-12905 from N.S.F.) 16 EVERETT C. OLSON, University of Chicago. Feeding mechanisms: Crossopterygians, amphibians, primitive reptiles. (15 min.) In spite of notable changes in proportions, composition, and dynamics of skulls between rhipidistian crossopterygians and primitive amphibians, fundamental jaw mechanics were but little modified. The two groups are adaptively similar with respect to feeding habits, a result of direct continuity without modification of feeding environments. After the origin of tetrapods modifications occurred, related on the one hand to critical modifications of the posterior part of the skull and on the other to adaptive changes related to shifts in feeding habits. In predaceous amphibians, labyrinthodonts in particular, the application of adductor force continued to lie far posterior, close to the jaw articulation. Depressor action appears to have become highly developed. Lateral jaw movements were restricted, with pterygoid and throat muscles playing a relatively minor role. Reptiles arose early among tetrapods, probably from the most primitive, technically amphibian stages. Two early trends are apparent. One (batrachosaur, diadectomorph) is marked by retention of the otic notch, forward (relative) movement of the articulation, vertical adduction, well forward on the jaw, and strong pterygoid action. The other (captorhinomorph, primitive synapsid) by closure of the notch, retention of posterior position of articulation and coronoid insertion of adductors, and strong development of pterygoid actions. In both, depressor actions remained relatively weak. From these types came the various specialized patterns of reptilian jaw mechanisms. 375 109 DAVID PECK, Johns Hopkins University. Effects of tissue organization upon the stability of synthetic properties of embryonic cells in vitro. (Introduced by M. S. Steinberg) (15 min.) The question of stability of cell types can be resolved to the following alternatives: either the maintenance of a distinct cell type is due solely to intrinsic factors, or the cell is induced to exhibit its characteristic properties by virtue of the intercellular associations to which it is subjected. The technique of tissue dissociation in conjunction with the method of tissue culture provides a powerful means of gaining more insight into this problem. With this in mind, neural retinas were removed from 6- to 14-day chick embryos and cut into small fragments. These were then either attached to the walls of the culture vessel with chicken plasma, or were first dissociated by means of enzymes and then cultured as a dispersed cell population in a synthetic medium. Within 10-24 hours 95-100% of the cells cultured as a dispersed population transformed into pigmented cells. This transformation was not observed in those cells which were part of intact fragments of neural retina. Under the electron microscope the pigment granules display the morphology and structure characteristic of melanin granules. Furthermore, distinct and dramatic alterations of patterns of metabolism were brought about by the dissociation of the neural retina. Experiments utilizing C14-glucose show that the dispersed cell populations lose the ability to synthesize at least three compounds, and gain the ability to synthesize one compound not synthesized by intact fragments. (Supported by contract AT(30-1)-2194 from the A.E.C.). 216 DAVID P. PENNEY, W. C. DIXON and D. I. PATT, Boston University. The cytology of adrenocortical regeneration in selected sites in the rat. (15 min.) Using adrenocortical autotransplants in different sites and recovered during early development after various durations of regeneration (usually 2, 4, 7,14, 21 and 30 days), we determined the following: an approximate measure of the extent of regeneration; microscopic observations of lipid, mitochondrial and nuclear characteristics; and an analysis by means of differential centrifugation of the mitochondrial and microsomal fractions. The above observations were made on the following combinations of adrenocortical transplant preparations and sites: ( a ) one-quarter gland intramuscular; ( b ) one-half gland intramuscular; ( c ) one-half gland mesenteric; ( d ) enucleated mesenteric; and in some cases ( e ) in situ enucleated. In these studies we found that the mesenteric site was more conducive to regeneration than the intramuscular site with a progressive increase in the mass of regenerated tissue as one compares sites a, b, c, d and e, respectively. Cells of mesenteric transplants developed sudanophilic lipid characteristics similar to those of the normal adrenal cortex earlier than cells in the intramuscular transplants. Under phase microscopy the 376 AMERICAN SOCIETY O F ZOOLOGISTS 99 RICHARD E. PHILLIPS and D. FRANK McKINNEY, Cornell University and Delta Waterfowl Research Station. Effect of testosterone on occurrence of some duck displays. (15 min.) Groups of week-old Pintail (Anas acuta), Mallard (Anas platyrhynchos), and Redhead (Aythya americana) ducklings of both sexes were injected daily with 1 to 10 mg testosterone propionate in oil. Equal numbers of controls received only the oil, and all were watched daily for the appearance of sexual displays. After 4 days of injections Redheads began to give many “head-throw” displays with calls; Pintail males first showed the “burp” display after the 6th day and frequently thereafter. Displays characteristic of courting parties of Pintail and Mallard were observed very rarely, and most of them not at all despite the large doses and long periods of treatment. It is suggested that testosterone is necessary for these displays but that they can only occur in the presence of the proper environmental stimuli. 162 PETER E. PICKENS, Institute of Marine Science, University of Texas. Variations in the heart rate of mussels from different habitats. (Introduced by T. H. Bullock) (15 &.) Measurements of heart rates at different temperatures have been made in two species of mussels, Mytilus edulis and M. califominnus collected from Mexico, California, Washington, and Alaska. When the acutely-determined Rate-Temperature curves of heart beat are compared, there are indications of thermal acclimation in latitudinally and intertidally separated populations of mussels during the summer and fall; that is, animals from colder waters or lower intertidally have higher heart rates at any temperature. During the winter and early spring, however, some populations show no or even reverse acclimation. When mussels are reciprocally transplanted to each other’s habitat, differences in heart rate between populations separated intertidally are eliminated within three weeks, between populations separated latitudinally within 4 to 6 weeks in most cases. The one group that does not show compensation after transplantation is a population of M. edulis from Alaska whose members survive poorly and do not grow at southern habitat temperatures, and have different temperature limits which cannot be changed by acclimation. This may be a physiological species or differences may develop during ontogeny. Attempts to obtain thermal acclimation in the laboratory have f d e d for all populations. However, changes i n rate can occur if the nutrient supply is changed. It is concluded that pure thermal acclimation of heart rate in mussels is either absent, occurs over a long period of time, or is masked by the effect of food, and that transplantation effects may be due to something other than temperature. (Supported by grants from the U.S.P.H.S. and N.S.F.) 96 ANTHONY R. PICCIOLO, University of Maryland. Sex discrimination in species of Colisa and Trichogaster. (15 min.) Vision, olfaction, sound and tactile stimuli were investigated as possible cues aiding in sex discrimination. No evidence was obtained to indicate that the fishes responded to olfactory stimuli or that they produced sounds of biological significance. Rather, sex discrimination is dependent upon the visual cues which include color patterns and markings, shape and the differential behavior (movements) of the sexes. Artificial dummies were utilized to study which characteristics of the fishes, other than their differential movements, served as cues which aided in discrimination. Besides the differential behavior exhibited by the sexes, it was discovered that the appearance of the fins was an important factor for sex discrimination in Trichogastet and that the color patterns and markings were important factors for sex discrimination in Colisa. Also, males exhibited more vigorous courtship responses to “‘female” dummies with bulging abdomens. (Supported by grants N.R. 104-489 from O.N.H. and MF-9945 from the U.S.P.H.S.) 53 D. F. POULSON and B. SAKAGUCHI, Yale University. Evidence concerning the nature of the “sex-ratio” agent in Drosophila. (15 min.) In experimentatl infections of normal Dies with the “sex-ratio’’ agent the majority of cases of unisexual progenies are detected in the first generation from the injected females. However, the SR condition may first appear only in the second, third, or later generations from some injected females. Sub-threshold effects, such as sporadic lethality, may appear early and persist for many generations in non-SR lines derived from some injected females. Thus the agent responsible for the SR condition may be present in latent form in apparently normal flies. That the SR agents so far studied are not species specific has been shown by Malogolowkin (personal communication) by experimental transfer among the sibling species of the willistoxi group and by us in the transfer from D. willistoni to D. melanogastet. The pattern of developmental disturbances appears similar in the several species. Tests of the distribution of the SR agent at different stages and in different tissues show it to be present at exceptionally high levels in the mitochondria and nuclear characteristics appeared the same in each site studied; however, the mitochondrial fraction of centrifuged 21- and 30-day transplants showed significantly more mitochondria than in intramuscular transplants of the same age. There were no significant differences in the microsomal fractions of the various sites studied. An indirect method was used to compute the percentage of viable cortical tissue in one-half gland intramuscular transplants. After 2, 4, 7, 14, 21 and 30 days of regeneration viable cortical tissue constituted 4, 7, 10, 55, 67 and loo%, respectively. (Supported by grant H-1965 from the U.S.P.H.S.) 377 ABSTRACTS blood of adult SR females of D. willistoni and D. melanogastet as well as in a new case of SR now being analyzed in D. nebulosa. Contrary to previous expectation the SR agent is present in high concentration in the blood of the rare surviving sons of SR females of D. willistoni as shown by infection tests, although such males do not transmit the SR condition to any of their progeny. Experiments on the effects of dilution of blood on incubation time and frequency of SR infections do not show the simple relations expected if the SR agent were a typical virus. Filtration of extracts of SR flies through Millipore filters gave no reduction in infections at 0.3 p pore size and 50% reduction at 0.1 ,u pore size. Phase microscopy of the blood of SR females of D. melanogaster, D. willistoni, and D. nebulosa shows the presence of minute motile granules and of very fine motile filaments (0.142 p by 4-8 B ) . The latter appear to possess the properties associated with small spirochetes, including Giemsa staining, Gram-negativity, penicillin sensitivity, etc. The fine filaments have not been found in the blood of any normal females of the species studied and are lacking in the blood of daughters of SR females whose progenies have been genetically disrupted, e.g., XXY? X Sevelen 8 in D. melanogaster. The very minute granules, but not the filaments, are present in the blood of the rare sons of SR females in D. willistoni. An electron microscopic study of these particulates has begun. (Supported by grant 6017 from N.S.F.) 172 JAMES B. PRESTON and DONALD KENNEDY, State University College of Medicine in Syracuse and Stanford University. Properties of spontaneously active units in the ventral nerve cord of the crayfish. (Introduced by William H. Telfer) (15 min.) Single units which discharged repetitively without intentional stimulation were isolated from the ventral nerve cord by intracellular recording methods in the proximity of the 6th abdominal ganglion. These “spontaneously” active units could be classified into three arbitrary groups; group I units in which interspike intervals varied less than 10 msec.; group I1 units in which interspike intervals varied within a range of 20-30 msec. with the majority of intervals being within a range of 10 msec.; and group I11 units in which the interspike intervals varied randomly without prominent peaks in interval distribution. Only units of groups I and I1 were studied. The frequency of “spontaneous” discharge in these units was usually between 5 and 10 responses per second. Group I units which maintained “constant” interspike intervals, in general, could not be discharged by sensory inputs while the majority of group 11 units could be discharged by appropriate sensory nerve stimulation. Both group I and I1 units discharged to direct stimulation when the stimulating and recording electrodes were placed in the same ganglionic intersegment. Evoked direct single spike activity in these units reset the spontaneous activity. In group I1 units, evoked single spikes from peripheral inputs reset the spontaneous rhythm of some units and i n other units evoked spikes were interpolated within the spontaneous rhythm without resetting the rhythm. In 4 of 20 units in which attempts were made it was possible to stop and start spontaneous activity by evoked discharges, (Supported in part by grant B-1608 from the U.S.P.H.S.) 22 C. LADD PROSSER, Bermuda Biological Station and University of Illinois. Mechanical responses of sponges. (15 min.) The oscula of many sponges contain spindleshaped myocytes in circular and radial bands. Oscular contractions were studied in both marine and freshwater sponges. The adequate stimulus is quick mechanical deformation. Responses are local, graded and show temporal but not spatial summation. Electrical stimulation of several sorts was ineffective. T h e oscula are sensitive to hydrostatic pressure in the canals. When stretched and held for a half minute, oscula maintained an extended form as with a catch mechanism. Attempts were made to record action potentials with several kinds of electrode, in sea water, oil and sucrose but no true potentials were obtained. Apparent electrical responses resulted from electrode movement and corresponded to a contraction time of 2-5 seconds and relaxation time of 40-60 seconds. Good contractions were obtained in mixtures of sea water with isotonic KC1 and in 0.05 M KCI in fresh water. It is suggested that the primitive contraction may be a direct response to mechanical deformation without membrane depolarization and without propagation. (Supported by N.S.F. and O.N.R. grants.) 153 W. PRYCHODKO and A. P. LONG, Detroit Institute of Cancer Research and Wayne State University. Effect of isolation on the body weight of laboratory mice. (10 min.) Only limited information i s available concerning the effect of housing conditions on the body weight of laboratory mice. A series of experiments was undertaken to determine how the latter could be influenced by the number of animals per cage and by availability of nesting material. Males and females of several inbred strains of mice were used in the study. It was found that isolation of males in bare cages resulted in a reduction of their body weight, when compared to controls which were kept 10-15 animals to a cage. Significant differences were observed. They persisted during the entire experimental period. The response of females to isolation was less pronounced. When the singly housed animals were provided with cardboard boxes and with nesting material, body weights intermediate between those of controols and isolated mice without nests were found. Our data indicate that ability to aggregate and availability of shelter influence body weight of mice and must be considered i n interpreting experiments with these animals. 378 A M E R I C A N SOCIETY OF ZOOLOGISTS 91 H. M. RADFORD and C. H. SAWYER, University of California, Los Angeles and Veterans Administration Hospital, Long Beach. EEG changes i n the rabbit rhinencephalon related to pituitary activation by intraventricular norepinephrine. (15 min.) Release of pituitary ovulating hormone has been induced in the rabbit by injecting norepinephrine into the third cerebral ventricle (Anat. Rec., 112: 385, 1952). More recent experiments indicate that the agent is effective via its action on the central nervous system (CNS) rather ,than directly on the adenohypophysis (Sawyer, 58). The present experiments were undertaken to determine whether specific regions of the brain might be implicated in the neuroendocrine response by revealing localized EEG changes following in traventricular injection of norepinephrine. In 13 mature female rabbits bipolar electrodes were implanted chronically into various regions of the brain and a permanent cannula into a lateral ventricle. Intraventircular injection of a neutralized solution of norepinephrine (0.75 mg) consistently induced ovulation in estrous but not in pseudopregnant rabbits. Characteristic EEG changes, followed by confirmed ovulation, werc observed regularly under the former conditions but not during pseudopregnancy in the same rabbits. The most dramatic EEG changes occurred in the olfactory bulb and its projection pathways, including a flattening of the record during the first 20-40 min. and a subsequent pronounced amplification of 40-50/sec. sinusoidal waves over the course of about an hour. During this period of localized EEG hyperactivity there were frequently sleep spindles in the frontal cortex, and the animal was immobile and very difficult to arouse. The results suggest that central nervous activation of the adenohypophysis by intraventricular norepinephrine is reflected in rhinencephalic EEG changes involving olfactory projections and that these effects are dependent on alterations in CNS thresholds by ovarian steroids . 125 RONDELL H. RHODES and H. CLARK DALTON, New York University. Histochemical patterns in developing pituitaries in two strains of Mexican axolotl, Siredon mexicanum. A comparison o f RNA and alkaline phosphatase contents is made between the black and white strains of the Mexican axolotl between stages 35 and 46. The patterns are associated with the beginning of secretory activity of the gland. Hypophyseal cells were classified according to the degree of RNA or alkaline phosphatase activity as determined by the amount of pyronin Y or cobalt sulfide precipitate within each cell: (large amount), +-t (moderate) and (trace). The and cells are considered active, whereas the f cells are considered inactive. Differential counts were made of these cells at each stage covered i n the study. In the black axolotl, the per cent of the total hypophyseal cells found to be active at stage 35 was 15.13 (RNA) and 45.54 (alkaline phos- +++ ++ + +++ phatase). At this same stage in the white axoltol, active cell constituency was found to be 41.54% (RNA) and 52.26% (alkaline phosphatase). Active cells in the black axolotl have increased 52.97% (RNA) and 25.31% (alkaline phosphatase) by the time stage 46 is reached. In the white axolotl, an increase of 12.88% was found in alkaline phosphatase but no increase was found in RNA. Whereas cells are present throughout the series, both RNA and alkaline phosphatase cells make their appearance at stage 41 which coincides with the time of onset of secretion. These cells increase with time, but the increase is greater i n the black axolotl than in the white. ++ +++ 210 M.T.M. RIZKI, Reed College. The nature of the autofluorescence of the f a t cells of Drosophila. (15 min.) As the time of pupation approaches, the autofluorescent pattern of the anterior fatbody of the larva of Drosophila meZanogaster becomes distinct from the remainder of the fat cells. Light blue fluorescent granules accumulate in the cytoplasm of the fat cells in the anterior fatbody in the normal Ore-R strain. This same pattern of differentiation between the anterior and posterior larval fat was found in a number of mutant strains which were examined : brown; white; cinnabar; cinnabar, brown; scarlet; rosy; red cell; claret. The light blue fluorescent material was absent from vermilion and vermilion, brown larval fat. These examinations suggested that the light blue autofluorescence might be due to the presence of kynurenine, since the latter would be expected in all of the mutant strains examined except v m milion. Confirmation of this fluorescent substance as kynurenine was obtained by comparing a known sample of kynurenine with the material from the anterior fatbodv utilizine uauer chromatography. (Supported *by grant RG-5285 from the U.S.P.H.S.) --- 267 M. T. M. RIZKI, Reed College. Intercellular effects of glucosamine-hydrochloride on tumor formation in Drosophila melanogaster. Various concentrations of glucosamine-hydrochloride have been fed to larvae of a tumorous strain ( tumrc) which develops melanotic masses in the posterior fatbody in the late third instar. Treatment with glucosamine-hydrochloride as early as the second instar alters the pattern of tumor formation. On a normal diet, the posterior fat masses of tuw larvae are encapsulated by blood cells, and the resulting accumulations appear as tmo large melanotic masses in the posterior region of the body. Larvae raised on glucosamine-hydrochloride contain many small free-floating melanotic aggregates. Glucosamine-hydrochloride under these conditions delays pupation and these larvae will live for several days with the free-floating masses. However, if these larvae are then returned to a normal diet, the small masses reaggregate to form larger masses and pupation occurs. The above observations together with histological examination indicate that feeding of ABSTRACTS glucosamine interferes with the adhesive properties of the cells involved in tumor formation. (Supported by grant RG-5285 from the U.S.P.H.S.) 21 MORRIS ROCKSTEIN and ARNOLD FINI(EL, New York University School of Medicine and Marine Biological Laboratory. Stellarin, a photosensitive pigment from the dorsal skin of the starfish, Asterias forbesi. (15 min.) Modikation in extraction procedures has yielded a highly purified preparation from the dorsal skin, with a D,i,/Dm, of as low as 0.2. This is a violet, photosensitive pigment with an absorption maximum at 523 mp, in a 2% digitonin solution at pH 6.8 to 11.3, which is rapidly converted to a peachcolored pigment with an absorption maximum at pH 490 m p , upon exposure to strong white light at constant temperature, for as little as 5 minutes. Storage in the dark at room temperature (25'C) for several hours produces a similar, but incomplete conversion from 523 to 490 pigment; similar storage at 0-2"C for extended periods of time failed to produce such effects. This indicates a weak thermolability, but a strong photosensitivity on the part of the pigment. Extraction into an acid digitonin solution (pH 3.0 to 6.5) gives a photostable pigment of deeply purple hue, with a peak absorption at 567 mp, which is convertible to the 523 n q ~pigment by alkalization with sodium bicarbonate or 1.0 NaOH. This shift in peak absorption is not reversible by further acidiilcation, however. Heating either the 523 or 567 pigment at 41°C for 5 minutes results in rapid, irreversible shifting to the 490 pigment to a deeply orange endpoint. These results indicate that there exist in the dorsal skin of this positively phototactic individual a light-insensitive (567) precursor and a light-sensitive pigment, stellarin, with a peak at 523 m+ (Supported by grant 6-11664 from N.S.F. and the New York University Graduate School of Arts and Sciences.) 268 M. ROCKSTEIN and R. SPRITZER, New York University School of Medicine and Marine Biological Laboratory. Light orientation in the starfish, Asterius forbesi. Young starfish, 1%inches in size, showed positive phototaxis to white light of moderate intensi t y only when exposed to such light during normal daytime hours. Attempts to reverse such responsiveness to light, by exposure to light at normally night-time hours and dark exposure during normally daylight hours, for a period of over 5 weeks, failed to shift the rhythmic phototaxis to a nightday response. However, such treatment did destroy the normal pattern of light responsiveness during normally daylight hours. Preliminary experiments involving exposure to light of specific wave lengths, ranging from 400 to 700 m,in 50 mp steps, gave consistently positive results only at 450 m p . (Supported by grant 6-11664 from the N.S.F. and Nonr-1497(00) from the Marine Biological Laboratory.) 379 15 DONN E. ROSEN, Florida State Museum and University of Florida. The jaw of cyprinodontiform fishes, a pre-acanthopterygian experiment in protractility. (15 min.) The evolution of the protractile acanthopterygian upper jaw from a relatively immobile isospondylous one apparently involved (1) a progressive shift forward of the anterior elements of the palatoquadrate arch from a postorbital to a preorbital position, and the resultant forward movement of the lower mandible, ( 2 ) freeing and enlargement of the premaxillae and exclusion of the maxillae from the gape of the open mouth, (3) consolidation and simplifkation of the subdivisions of the mandibular muscles, and (4) the origin of new ligaments from the maxilla to the mandibular muscles and to the ethmoid and/ or palatine bone, and from the upper end of the premaxilla to the palatine. The jaw mechanism of cyprinodontiform fishes appears to be a specialized offshoot from a pre-acanthopterygian type, and represents an early experiment in protractility. The departure of ancestral cyprinodontiforms from the main line of acanthopterygian evolution evidently occurred before the premaxillary-palatine ligament was established. The cyprinodontiform jaw, as a consequence of lacking this ligament, may have had much less adaptive potential than the basic acanthopterygian mechanism that it has paralleled in most respects. The absence of a premaxillary-palatine ligament, however, has made possible the development of a highly effective mechanism for nibbling with the mouth parts fully protracted. This specialization has been accomplished in part through the insinuation of the greatly expanded lower premaxillary arm between the maxilla and lower mandible, the growth of a new ligament between the lower ends of the maxilla and premaxilla, and replacement of the primitive maxillary-mandibular ligament by a premaxillary-mandibular connection. 104 R. M. ROSENBAUM and CHARLES WEISS, Albert Einstein College of Medicine. Autolytic activity during limb regeneration in Triturus: a histochemical approach. (15 min.) The forelimbs of adult Triturus were amputated through the humerus, either leaving the proximal portion or removing it. After varying periods (from 1 to 54 days), the region of wound repair or of the accumulation or regeneration blastema was removed and fixed in Carnoy or acetatebuffered formalin. Paraffin sections were stained with various molar concentrations of methylene blue-eosin at controlled pH; frozen sections were stained for acid phosphatase activity, employing a method modified after Gomori, and for aminopeptidase activity using leucyl-haphthylamide as a substrate and Garnet GBC as a coupling agent. The increased activity of these hydrolytic enzymes was considered as demonstrating autolytic changes associated with localized cell death. In unoperated limbs, aminopeptidase activity is confined to the outermost epidermal cells, the mucus glands and the nerves; acid phosphatase activity is normally present in macrophages. Immediately 380 AMERICAN SOCIETY O F ZOOLOGISTS following amputation, only the cut ends of skeletal muscle fibers show intense activity for aminopeptidase while only slight activity for acid phosphatase can be detected. As cut muscle fibers degenerate, aminopeptidase activity increases proximally until formation of the accumulation blastema at about 9 days; acid phosphatase activity is negligible. As the proliferative phase sets in, the basal epidermis in the vicinity of the original wound becomes highly active for both enzymes. This heightened activity persists until redifferentiation of the blastema becomes evident. During the final reorganization of the blastema, hydrolytic enzyme activity appears indicative of subtle autolytic changes, localized cell death and similar degenerative phenomena related to formative processes during regeneration. (Supported by grant RG-5483 from the U.S.P.H.S. and by a Medical Student Fellowship awarded by the National Foundation.) 269 LAURENS N. RUBEN, Reed College. Further studies on implant-induced supernumerary limbs in urodeles. Sixty adult Triturus viridescens were divided into 4 groups. One implant (approximately 2 mm in diameter) was placed in each hindlimb of every host in accordance with techniques described by Ruben, (J. Exp. Zool., 128: 1955). Hosts in one group bore two implants of adult Rana pipiens limb cartilage-bone (phalanges and metacarpals), while members of the remaining three groups carried frog limb muscle, sciatic nerve axone, and limb skin, respectively. Implant volumes were kept equal in all groups. Histological assays of all 120 limbs were made at 82 days post-implantation. Small host cartilage nodules, which were physically associated with the cartilage rather than the ossified portions of the donor implant, were induced to form in 40% of those limbs bearing frog cartilage-bone. Host cartilaginous formations developed in response to donor cartilage-bone are less extensive than those induced by frog kidney. Frog limb muscle, sciatic nerve axone, and limb skin did not stimulate host limb morphogenesis in these experiments. There was less evidence of implantation with muscle than with anything else, i.e. absence of visible signs of implant material or of any disturbance of host tissue was the usual result. Muscle implant sites were relatively flat by one week post-implantation. No sloughing had occurred. Nerve implants were generally encapsulated, the limb response being fibrous rather than cartilaginous in character. Normal adult frog kidney remains the most effective donor material thus far utilizcd in bringing about urodele supernumerary limb formation. (Supported by grant C-2913 from the U.S.P.H.S.) 270 FRANK T. RUGGIERO and WALTER S. TYLER, University of California, Davis. Width of the proximal tibial epiphyseal lines from achondroplastic and control rabbits. The width of an epiphyseal line has been frequently used as an indication of its activity. The widths of the proximal tibial epiphyseal lines from 14-day-old achondroplastic dwarf and control rabbits were measured in a study of their relative activities. This type of achondroplasia in the rabbit was first described by Crary and Sawin (J. Hered., 43: 255, 1952). Foundation stock was obtained from the Jackson Memorial Laboratory courtesy of Dr. P. B. Sawin. Nine complete litters containing 23 dwarfs and 36 control rabbits were studied. Thus the controls were full siblings of the dwarfs and were reared under nearly identical conditions. The tibias were removed, split sagittally on the midline, and fixed in Bouin’s solution. Paraffin sections were prepared and stained with toluidine blue. All measurements were made from the epiphyseal plate of bone to the bone of the developing diaphyseal trabeculae. Ten measurements were made along the entire length of the epiphyseal line and a n average width calculated. The mean and standard error for the 23 dwarfs was 748 & 17.3 p, that of the 36 controls was 808 f 18.4 p. Student’s t-test was applied and the difference of the means was found to be significant at the 5% level, but not at the 1% level. It is concluded that the epiphyseal lines of the dwarfs are relatively less active than those of the control rabbits. These results are in agreement with observcd differences in the growth rates. (The work of Mr. Ruggiero was supported by N.S.F. through the Summer Biology Program for Secondary School Students. Supported in part by grant A-2626 from the U.S.P.H.S.) 271 ROBERTS RUGH and ERICA GRUPP, Columbia University. Congenital effects following low level x-irradiation. Congenital effects may be produced at any time prior to the completion of histo- and organogenesis by x-irradiation. There is no “critical period” for the production of C.N.S. effects, and exposures as low as 15 roentgens have caused the severe anomaly of exencephalia or herniated brain in mouse embryos, irradiated during the very early cleavage stages. This anomaly has been produced by x-irradiation of grandparental sperm, grandparental ova, or by x-irradiation of any stage prior to the completion of neurogenesis. It has also been produced by radio-mimetic substances, and by vitamin imbalance of the preg nant mammal, but it is most consistently produced by even low levcls of x-irradiation. An exposure to as little as 5 roentgens at 0.5 day after conception, prior to the first cleavage in the mouse, results in about a 10% increase in intra-uterine death. After 8.5 days, when neurogenesis is completed, such anomalies as exencephalia cannot be produced, but other effects are noted, particularly in tissues and organs that have not completed their development. It is believed that litter mates of those exhibiting such anomalies, while they may not show any gross effects, are themselves neurologically deficient and may manifest effects with electroencephalography or behavior tests, even though there may be no histological corollaries. For this reason it is recommended that pelvic x-ray of the pregnant human female be discouraged, particu- 381 ABSTRACTS larly during the first trimester, and that in nonpregnant human females such examinations be limited to the first 9 days after the onset of menstruation, in order to avoid any unrecognized pregnancy. 176 OLIN RULON, Northwestern University. The extension of fertilizability and life in sand dollar eggs with cobalt, cysteine and thioglycolic acid. (15 min.) Under normal laboratory conditions the eggs of Dendraster excentricus lose their capacity for fertilization within one day after removal from ripe ovaries. Previous work by the author has shown that fertilizability may be extended to approximately 7 days in certain sea water solutions of cobaltous chloride and to 13 or more days by the addition of glutathione to the cobalt (50 cc of 0.05% glutathione plus 50 cc of M/200 cobaltous chloride). In the present work other reduced sulfur compounds were used which enhanced the effect of cobalt even more than glutathione. Neither cysteine hydrochloride (0.00625%) nor thioglycolic acid (0.005% ) had more than minor effects on fertility when used alone. With cobalt the two most effective combinations were (1) cobaltouscysteine (50 cm3 of 0.0125% cysteine hydrochloride plus 50 cm3 of M/200 cobaltous chloride) in which 50% of the eggs were fertilizable at 21 days and (2) cobaltous-thioglycolic acid (50 cm3 of 0.01% thioglycolic acid plus 50 cm3 of M/200 cobaltous chloride) in which 50% were fertilizible at 25 days. The work suggests that cobalt, cobaltous-cysteine and cobaltous-thioglycolic acid prevent the deterioration of fertilizability by uniting with (and preventing the oxidation of) thiol groups at the egg surface. 52 B. SAKAGUCHI and D. F. POULSON, Yale University. Transfer of the “sex-ratio” condition from Drosophila willistoni to D . melanogaster. (Introduced by G. E. Hutchinson) (15 min.) The maternally transmitted condition known as “sex-ratio’’ (SR) in D . willistoni was demonstrated by Malogolowkin, Poulson and Wright (Genetics, 44: 59-74, 1959) to be transferable to previously normal strains of this species. To facilitate analysis of developmental genetic aspects of SR, attempts were made to transfer SR from D. willistoni to D . melanogaster. This has been accomplished using as recipients females of two wild type strains, Ore R inbred and Sevelen inbred, a triploid strain carrying attached-X chromosomes, and a diploid strain with the same attached-X chromosomes (y2 sc woec/ Y ? X y31dsc* d m B 8 ) . Hemolymph (0.05-0.08 pl) from SR females of a strain maintained for many generations by mating to males from the Barbados-3 strain of D . willistoni was injected by micropipet into the abdomens of 1- to 2-day-old virgin females of the above strains. Individual females were mated to males from their own strains and were transferred to new culture medium every two days. Unisexual progenies began to appear in many instances even in early broods. From these, lines of SR have been maintained by mating with males from the corresponding normal strains. Some of these lines have proved much more stable than others. One of the best is a line derived from the attached-X strain demonstrating that the Ychromosome is not of primary importance in the lethal disturbances associated with the SR agent. That the persistence of SR in D. melanogaster is dependent on the genotype of the flies is clearly demonstrated through the replacement of chromosomes by crossing females of the new strains of SR to males from different normal strains. Crosses of SR females of the attached-X strain to Ore R males continued to yield unisexual progenies in the first and subsequent generations, while parallel crosses to Sevelen males led to the immediate appearance of males in the progenies and disruption of the SR condition. These and other cases are being analyzed in detail. (Supported by grant 6017 from N.S.F.) 200 HIDEMI SATO, Dartmouth Medical School. A morphological study on the mitochondria of Tehahymena g e k i i W. (15 min.) About 80% of the mitochondria of Tehahymena geleii W are arranged in a layer of ectoplasm which is located just under the pellicle and surface ribs, and, another 20% are localized around the end of the gullet and macronucleus. This trend is revealed both i n osmotrophic and in phagotrophic conditions. Generally, the mitochondria have an oval or elliptical shape and are 0.8 to 1.3 p in length. The are osmiophylic, sensitive to fat solvents and react faintly with Janus green B. Sedar & Rudzinska (J. Biophys. Biochem. Cytol., Suppl., 331439, 1956) and other authors have showed their microvilli clearly. The population density of mitochondria in the ectoplasm is 35 to 40 per 100 p2 and does not depend on cell stage. The total number of mitochondria is 600 to 800 in daughter cell, and increases gradually during interphase, finally reaching 1200 to 1500 at the prefission stage. When the cell is cultured in very rich nutrient at high temperature, the generation time is about 20% shorter than usual. In this case, the population density of mitochondria decreases gradually during interphase, but recovers its original value by the prefission stage. The lowest density is 28 per 100 p2 at late interphase. At this time the mitochondria change from oval to thread shaped and they lose their original localization. They regain their initial appearance when the cell recovers the original density during the prefission stage. The change in mitochondrial shape from oval to threadlike in cells whose division has been synchronized by temperature shifting occurs about 30 minutes before the first division. 14 BOBB SCHAEFlFER, American Museum of Natural History. The origin of the holostean feeding mechanism. (10 min.) The shift from the chondrostean to the holostean feeding mechanism mainly involved modifications related to the adduction of the mandible. 382 AMERICAN SOCIETY O F ZOOLOGISTS In most palaeoniscoids and some subholosteans the dorsal part of the adductor mandibulae was contained in a chamber composed principally of the maxillary, the preopercular with its internal lamina closing the chamber dorsally, and the laterally curved palatoquadrate complex. The holostean condition was approached in chondrosteans with a vertical suspensorium, a reduced maxillary, and a preopercular with no internal lamina so that the adductor chamber opened dorsally. In such forms part of the adductor possibly arose from the braincase. The chondrosteanholostean transition further involved freeing of the maxillary from the cheek and palate, separation of the cheek elements from the preopercular, flattening of the palatoquadrate complex behind the adductor and development of a coronoid process on the mandible. The adductor mandibulae increased in size, in area of origin and in degree of subdivision. Although the major part of this muscle s t i l l entered the mandibular fossa as in the palaeoniscoids, one subdivision inserted on the coronoid process. As a result of these modifications, the holostean jaw mechanism, during adduction, is more effective than the chondrostean. The reasons are: (a) increase in the power of the adductor, (b) greater range in the angle of application of this muscle on the mandible and, related to this, ( c ) a marked increase in the torque about the jaw articulation. 29 BERTA SCHARRER and MARIANNE von HARNACK, Albert Einstein College of Medicine. Castration effects in the insect, Leucophaea mademe. (15 min.) Earlier work demonstrated an accumulation of characteristically staining inclusions in the “B type neurosecretory cells” of the subesophageal ganglion of ovariectomized Leucophaea (B. Scharrer, Trans. N. Y. Acad. Sci., 17: 1955). These and similar inclusions i n other neurons are PASpositive following saliva treatment. Comparable castration effects have been observed in several non-nervous cell types. Cytoplasmic inclusions showing the same properties with the techniques used, are markedly increased in the corpora allata, the fat body, and the musculature of gonadectomized females. While it is not established that the PAS-positive, saliva-resistant materials found in various tissues of Leucophaea are chemically identical, their accumulation after ovariectomy suggests a common denominator. These deposits may be related to a change in general body metabolism in the absence of growing ova, or they may be an expression of the endocrine disturbance brought about by the removal of the ovaries and the concomitant imbalance of the corpora data. It is significant that in the males, where the corpus allatum-gonad axis does not operate as in females, fat body, musculature, corpora allata, and nervous elements do not respond to gonadectomy in the same manner as in females. (Supported by grant C-3413 from the U.S.P.H.S. ) 87 GEORGE T. SCOTT and LEWIS K. NADING, Oberlin College and Marine Biological Laboratory. The relative effectiveness of phenothiazine tranquilizing drugs causing the release of MSH in the frog. (15 min.) Nine phenothiazine ataraxic drugs now used in medical practice were found to cause melanophore dispersion in the intact frog; one was shown to be ineffective. All drugs employed were ineffective in the hypophysectomized frog. The drugs, therefore, are effecting the release of MSH by direct action on the hypophysis or indirectly via brain centers. Minimal effective doses of the drugs were determined and were as follows in milligrams per 100 grams: fluphenazine (Permitil) 0.09, trifluoperazine (Stelazine) 0.2, perphenazine (Trilafon) 0.4, thiopropazate (Dartal) 0.4, chlorpromazine (Thorazine) 0.6, triflupromazine (Vesprin) 1.0, methoxypromazine (Tentone) 1.2, prochlorperazine (Compazine) 1.3, promazine (Sparine) 2.3, mepazine (Pacatal) not effective. Correslations of relative milligram potency for melanophore dispersion with group substitutions on the phenothiazine nucleus were observed. A parallel with milligram potency for therapeutic control of psychiatric disorder was noted. (Supported by grant My-3903 from the U.S.P.H.S.) 83 EARL SEGAL, Rice University. Acclimation in molluscs. (30 min.) During the past few years reviews by Bullock, Fry, Precht, and Prosser have appeared, wholly or in part concerned with compensatory changes in poikilothermic organisms in response to persisting temperature changes i n the environment. If we are concerned solely with body temperature, poikilotherms are conformers. But, if we examine the rates of reactions or the tolerance levels to temperature extremes, we discover compensatory responses in activity rates and shifts in tolerance levels regardless of the passivity of body temperature. This phenomenon, referred to as acclimation, we may consider a homeostatic tendency in response to a changed environment. Therefore, whether the environmental change is a naturally occurring one due to changing seasons, latitude, and migeographic habitat, or a single factor change in the laboratory, the organisms acclimated to cold will show a higher metabolism, or other activity rate, at a given temperature than organisms acclimated to warmer temperatures. Cold and warm acclimation may also bring about a shift in tolerance levels. Representatives of at least two classes of mollusca, gastropods and pelecypods, from marine, fresh water, and terrestrial habitats show varying degrees of acclimation of rate functions and shifting of tolerance levels. The distribution of acclimated responses in the mollusca; the biological significance of differences in the ability to acclimate; and the limits of acclimation and its possible significance in the distribution of ~- the species will be discussed. (Supported by grant G-5943 from N.S.F.) ~~~ ABSTRACTS 143 KENNETH C. SHAW, University of Michigan. An experimental analysis of the singing behavior of the true Katydid (Pteruphylla: Tettigoniidae). (15 min.) The sound of a male katydid apparently has both inhibiting and stimulating effects on his own sound production and that of other male katydids. These effects are apparent in male katydid chorusing which consists of imperfect alternation of song phrases. In addition, the pulse number of the song phrases of a katydid may change during alternation of song phrases with another katydid or when he is singing alone. Some of the factors involved i n phrase alternation and pulse number change i n the songs of male katydids have been determined by analyzing tape recordings of katydids responding to: (1) the songs of other katydids, and (2) artificial songs produced by an apparatus which allowed manipulation of the various parameters of the song. From the analysis of these tapes, hypotheses have been formulated concerning the probable function, mechanism, and origin of phrase alternation and pulse number change i n the songs of these katydids. 198 R. W. SIEGEL and L. LARISON, University of California, Los Angeles. Induced illegitimate mating in Paramecium bursaria. (15 min.) Conjugation takes place when sexually mature paramecia of complementary mating types are brought together; cells which belong to a given mating type do not normally conjugate among themselves. However, clone Wu-67 of P. bursaria is exceptional for intraclonal conjugations (Wu67 X Wu-67) can be induced following contact with cells of a complementary type. Various observations indicate that contact does not induce cells of Wu-67 to change to a new mating type specificity, hence these exceptional pairs are termed “illegitimate.” The frequency of illegitimate pairs varies directly with the concentration of cells in a population of potential mates and with the number of cells of the complementary mating type present. Cell-free fluids and breis apparently cannot induce illegitimate mating. The relationship of these observations to Miyake’s earlier studies of chemically induced intraclonal conjugations in other species of Paramecium will be discussed. (Supported by a grant from N.S.F. and by Cancer Research Funds of the University of California.) 383 With the onset of adult development incorporation increased two-, 5-, 8- and 200-fold in midgut, fat body, epidermis and blood respectively. Two days before adult emergence, all tissues were highly labeled except the fat body, which is being resorbed during that period. The specific activity of egg proteins of the old adult (8 days after emergence) was the highest obtained during these studies. In view of Harvey and Shappirio’s work on injury metabolism in Cecropia and since the amino acid was injected into the silkmoths, the incorporation of valine into injured brainless diapausing pupae was also investigated. Injury raised incorporation into all tissues to the level of developing adults. An equal increase was also caused by injection of the molting hormone ecdysone. Indeed, the hormonally treated animals showed the first signs of adult development, retraction of the epidermis. The in d u o synthesis of a single protein was also studied. Reduced cytochrome c was extracted from thoracic muscles (Tuppy, H., 2. Naturforschung, 12: 784,1957). Its absorbency was measured at 550 m in the reduced and oxidized states. Although muscle formation begins on the 11th day after the initiation of adult development, with these methods, cytochrome c was first detected on the 17th day. f t increased in amount during the next 5 days, and leveled off in the adult. (Supported by postdoctoral fellowship 5576 from the U.S.P.H.S.) 225 ROBERT F. SLECHTA and ARTHUR B. CALLAHAN, Boston University. Blood pressure and flow characteristics in the microcirculation of the hamster cheek pouch with sodium pentobarbital anesthesia. (10 min.) Golden hamsters (Mesocricetus auratus) were anesthetized with single intraperitoneal doses (9.0 mg/100 gm) of sodium pentobarital (Nembutal, Abbott). Blood velocites were measured in small vessels (16-80 p diam.) of the cheek pouch by a modification of the Hugues method (J. Arch. Int. Physiol., 61: 565, 1953). Correlative data on systolic blood pressure and heart rate were determined by femoral cannulation and EKG recording respectively. During the first 20-30 minutes of the period of anesthesia (50-120 min.), blood velocity in arterioles dropped 2540% from estimated normal, unanesthetized levels (6-7 mm/ sec.) after which there was a gradual and rather consistent rise to normal when the animal awoke. 204 Similar effects were noted on blood velocity in DOROTHY M. SKINNER, Yale University. Pro- venules but depression of flow rates was much tein synthesis in the Cecropia silkmoth. (In- less marked (30-60%). Heart rate slowed as troduced by D. E. Bliss) (15 min.) much as 20% during the first 20-30 minutes, but The in uiuo incorporation of valine-l-C14 into rose to normal values by the end of the period the proteins of various tissues of the Cecropia of anesthesia. Systolic blood pressure dropped silkmoth during its life cycle and under various 2 0 4 0 % within the &st 20 minutes, but therephysiological conditions was investigated. Tissues after rose quite steadily until the end of the peexcised from diapausing pupae 24 hours after in- riod of anesthesia when normal levels were jection of labeled valine contained small amounts reached (av. 110 mm Hg). (Supported in part of the label. The specific activities (counts per by grant H-3087 from the U.S.P.H.S. and conminute/mg) of the tissues were as follows: blood, tract AF49(638)-44 from the Air Force Office of 2; fat body, 100; epidermis, 340; midgut, 500. Scientific Research.) 384 AMERICAN SOCIETY OF ZOOLOGISTS 178 ARLAN E. S. SMITH and A. M. SCHECHTMAN, University of California, Los Angeles. Protein changes during early amphibian development. (15 rnin.) Jelly and membranes of mid-gastrulae (Stage 11) and neurulae (Stage 14) of R a m pipiens embryos were removed enzymatically. The jellyless embryos, without prior homogenization or extraction, were preliminarily packed by centrifugation at 200 x g for three minutes. All excess fluid above the embryos was removed. The packed embryos were then centrifuged for 1V2 hours at 105,000 x g and the supernatant fluid recentrifuged for one hour. All materials were analyzed by starch gel electrophoresis using 0.03 M borate buffer, pH 8.6, immediately after centrifugation. Avoidance of extraction media is of prime importance. Use of distilled water, 0.15 M sucrose, or Holtfreter’s solution in a ratio of one volume of solution to one volume of embryos markedly reduced the number of electrophoretic components. By avoiding the use of any extraction medium, and obtaining fluid from the tissue itself (“protoplasmic fluid”) it was possible to discern a relatively large number of components. Protoplasmic fluid from gastrulae contained 20 different electrophoretic components; 12 migrated toward the anode and 8 toward the cathode. Protoplasmic fluid from neurulae contained 23 electrophoretic components; 14 migrated toward the anode and 9 toward the cathode. It is clear that new components must arise between the gastrula and neurula stages. Due to the degree of variation encountered, it is not possible at present to conclude that there is a loss or alteration of existing components in the transition from gastrula to neurula. On the basis of position and relative concentration most of the components from the gastrula appear to be similar to those from the neurula. On the basis of average mobility, however, the components from the two stages appear to be generally different; the difference is perhaps attributable to minor variations in molecular structure. (Supported in part by grant ‘2-6131 from N.S.F.) 13 STEWART SPRINGER, U.S. Fish and Wildlife Service. Dynamics of the feeding mechanism in sharks. (Introduced by Perry W. Gilbert) (15 rnin.) The more primitive sharks with amphistylic jaw suspension are presumed to tear or cut off portions of prey, too large to swallow entire, by lateral shaking motions of the head region or by twisting motions involving the entire body. Some of the more modern sharks with holostylic jaw suspension, such as the tiger shark, behave similarly. Here the effectiveness of the upper jaw is enhanced, making deeper and cleaner cuts possible, by the protrusibility of the upper jaw. The anterior portion of the pterygoquadrate moves away from the chondrocranium on processes of the pterygoquadrate which limit its lateral movement with respect to the chondrocranium. Serrate teeth, similar in both jaws of the tiger shark plus the abiLity of this shark to twist and spin make this “cut-off mechanism very effective. Some other galeoid sharks having protrusile upper jaws are handicapped by an inflexible trunk region and large, stiff pectorals which limit twisting. Here the lower dentition is more or less modsed for holding, and it has been observed that the cutting effect of the serrate upper dentition is achieved by a vibratory movement of the entire upper part of the head region. This appears to be transmitted to the upper jaw through its processes. In the few instances in which observation has been possible, a functional relationship has been found to exist between body and fin form and the structure and armament of the jaw cartilages. 107 F. E. STOCKDALE and HOWARD HOLTZER, University of Pennsylvania School of Medicine. The formation of multinucleated myotubes. (15 rnin.) How skeletal muscle becomes multinucleated has been attributed to several processes : mitosis without cytoplasmic division, amitosis and fusion of cells. Microspectrophotometric evidence indicates that neither mitosis nor amitosis occurs in adult regenerating skeletal myotubes and it has been proposed that nuclei in embryonic myotubes do not divide mitotically or amitotically (Holtzer, ‘56). The following experiments were performed to determine the source of nuclei in myotubes. Thigh muscle from 10 day chick embryos was trypsinized into a suspension of mononucleated cells and plated on coverslips. Twenty hours later the mononucleated cells were exposed for 30 minutes to tritiated thymidine, a precursor of DNA, rinsed i n BSS, then plated in fresh medium and cultured until multinucleated myotubes appeared. In another series myotubes were exposed to labeled thymidine for 30 minutes and fixed. Autoradiographs were made of both series. In the first experiment, where the cells were exposed as mononucleated cells, the myotubes which formed three or 4 days later contain a random mixture of labeled and unlabeled nuclei. This indicates that mononucleated cells become incorporated into myotubes and as mononucleated presumptive myoblasts they synthesize DNA. In the second experiment nuclei in the myotubes show no uptake of the thymidine. Presumably once nuclei are in myotubes they do not synthesize DNA. Thus neither mitosis nor amitosis can account for multinucleated myotubes. Fusion of cells is the probable basis for these results. (Supported by grants B-493 and B-1629 from the U.S.P.H.S. FES. : Medical Student Research Fellow of the National Foundation; H.H.: Scholar in Cancer Research of the American Cancer Society, Inc.) 144 JOHN F. STOUT, University of Maryland. The significance of sound production during the reproductive behavior of Notropis analostanus. (15 rnin.) Notropis anaEostanus males produce two different sounds during reproductive behavior. One sound, which is similar to a “knock,” is produced ABSTRACTS in a rapid series during fighting behavior with other males of the same species. The other sound is a “purring-like’’ sound and is produced during courtship of the female. In a series of controlled experiments these two sounds were played back at the normal level of production to the fish maintained in laboratory aquaria under the following conditions: (a) 10-12 males; (b) two males; ( c ) one male and two females; ( d ) one male confined to a gallon jar and one unconfined female. When the sound was played back it increased the occurrence of the behavior pattern with which it was normally associated. Thus, this species of fish can discriminate between the two sounds. (This research is supported by grants from O.N.R. (N.R. lO4-489), the U. S. P. H. S. (B-1668), the Sigma Xi Resa Research Fund, and by a N.S.F. Summer Fellowship for Graduate Teaching Assistants.) 65 ANDREW G. SZENT-GYQRGYI,Marine Biological Laboratory. Proteins of molluscan muscles. (15 min.) The smooth adductor muscles of a number of molluscs and the byssus retractor muscle of the Mytilus eduli contain paramyosin, a fibrous structure protein, in about equivalent amounts with actomyosin, also present in the same muscles. The actomyosin of these muscles behaves very similarly in first approximation to the actomyosin of vertebrates. Paramyosin has not been found in vertebrate muscles. This unique protein characteristically present i n “catch muscles” does not react in a specific fashion with adenosine triphosphate, actin or myosin and is unlikely to participate in the contraction process proper. Paramyosin behaves as a fully coiled a-helix, has a characteristic periodicity, and shows a sharp phase transition at neutral pH, depending on ionic strength. These, and other properties which will be described, may explain the ability of the catch muscles to maintain large tensions with no apparent energy requirement. The active contraction is assigned to the actomyosin component, while the change in elastic properties of the muscle, during the catch state, is derived from the in situ crystallization of paramyosin. 40 ETHEL TOBACH, L. VROMAN, G. TURKEWITZ and T. C. SCHNEIRLA, American Museum of Natural History. Infantile experience with specific visual stimuli as related to later differential approach responses in rats. (15 min.) Wistar strain rats were raised in two types of situations: (1) cages with wire-mesh walls and ( 2 ) cages with transparent and opaque plastic walls. In the plastic cages, a black disc encircled the water-bottle opening, a black triangle contained the food opening. The wire-mesh cages lacked such patterns. Animals were assigned to three groups; wire-mesh; plastic cage; and plastic cage with scheduled wall changes. At weaning (25 days of age), all animals were observed for 10 minutes in a test apparatus for frequency of nosing blank walls, disc, triangle, another familiar stimulus and a new stimulus. Wire-mesh cage animals nosed the blank walls and “new” stim- 385 ulus most frequently; the two groups raised in the plastic cages nosed the triangle more frequently than did wire-mesh cage animals, and nosed familiar stimuli more frequently than unfamiliar. (Supported by grant M-1441 from the U.S.P.H.S.) 208 W. S. TYLER, L. M. JULIAN and P. W. GREG ORY, University of California, Davis. Standard values of metacarpal indices for achondroplastic brachycephalic dwarfs and controls. (15 min.) Indices derived from metacarpal lengths and widths are of value in classifying brachycephalic achondroplastic dwarfs and non-achondroplastic controls (Tyler, Julian and Gregory, Am. J. Anat., 101: 1957). Since there are several distinct forms of achondroplasia that are genetically related and conditioned it is essential to separate the different components of the complex from each other and from non-achondroplastic controls. This study concerns 166 brachycephalic dwarf bulls, heifers, and steers, and 4 groups of control heifers, steers, cows, and veal calves totaling 178. The indices investigated are total length/ diaphysis length (TL/DL), total length/diaphysis diameter (TL/DD), and diaphysis length/diaphysis diameter (DL/DD). Dwarfs and controls were each subdivided; those with open metacarpal epiphyses were placed in one group and those with closed were placed in another. Sex and castration in the dwarfs have little effect, if any, upon the indices but may be effective in controls. Age per se has little effect but closure of the epiphyses has a significant effect. Each of the three indices consistently separates the achondroplastic mutants from the controls and the difference in all cases is significant at the 1%level. When the indices of specific control groups are compared the difference is slight but highly significant in each test. The causes of the differences have not been determined but they probably arise from several sources. The heifers, cows, and steers are regarded as selected populations while the calves are regarded as unselected. (This work was done in collaboration with the W-1 project and supported in part by grant A-2626 from the U.S.P.H.S.) 133 H. E. VAN HEYNINGEN, Brown University. The initiation of thyroid function in the mouse. (Introduced by J. Walter Wilson) (15 min.) The problem of the initiation of thyroid function in the mouse has been approached by determining the 24 hour 1131 uptake and the chromatographic distribution of the radioiodinated amino acids in the thyroid of fetal mice of different prenatal ages. Routine H and E and autoradiograph slides were also prepared of the fetal thyroids. The thyroid of 15-day-old mouse fetuses consists of cords of cells and does not accumulate iodine. The thyroid of 16-day-old mouse fetuses collects a small but significant amount of iodine, which is concentrated predominantly in small irregular droplets of colloid between the cells. This iodine becomes incorporated into MIT and DIT, but no thyroxine was found. The thyroid of 17-, 18and 19-day-old mouse fetuses contains colloid- 386 AMERICAN SOCIETY OF ZOOLOGISTS Wed follicles as well as inter- and intracellular droplets of colloid and the iodine taken up is incorporated into MIT, DIT and thyroxine. The relative amounts of the radioiodinated amino acids do not differ between 17-, 18- and 19-day old fetal thyroids, which shows that thyroxinogenesis has begun fully at 17 days. The development of thyroid function takes place therefore between 15 and 17 days of age. The 16-day results show that the secretion of colloid precedes the formation of follicles and that the production of thyroxine begins later than the organic binding of iodine to MIT and DIT. (Supported by grants CRT-5007 and C-510 from the U.S.P.H.S.) 84 P.B. VAN WEEL, University of Hawaii. Comparative physiology of digestion in molluscs. (30 min.) The concept that molluscs have an extraordinary enzyme equipment, particularly with respect to carbohydrases (such special enzymes like inulase, xylase, lichenase, cellulases, chitinase, etc.) must probably be changed. Florkin and coworkers have demonstrated that cellulase and chitinase are of bacterial origin and are not secreted by the molluscs. Morphological specialization of digestive glands as a rule does not mean physiological specialization in enzyme production, although in a few cases a special secretion does occur (Dolium, Conus, Cephalopoda). The midgut gland is the main seat of enzyme production and of resorption. Permeation through the wall of the intestine happens apparently along lines of diffusion. The effect of special diets on enzyme production is poorly understood. The enzyme equipment and secretion seems to “fit” the normal diet and a normal change of diet goes hand in hand with a change in enzyme production: immature Achatina fdica, predominantly herbivorous, produces slightly more amylase, but definitely less proteases, than the mature, omnivorous snail. However, mature snails, when fed on special diets for a long period, do not show a “fitting” adaptation of their enzyme production, at least not with respect to protease and cathepsin. Starch-fed snails produce more of these enzymes than protein-fed ones. The special diets do affect the utilization of the food, in that after 3 weeks of dieting a decrease in utilization of both starch and protein occurs. Apparently some unknown nutritional requirements are lacking i n these diets. Although rhythms in secretion do occur, nothing is known yet if and how these affect the feeding habits of the molluscs. 272 G. LAWRENCE VANKIN and H. CLARK DALTON, New York University. Analysis of tail darkening in hypophysectomized urodele larvae. Following hypophysectomy by extirpation of Rathke’s pouch ectoderm melanophores i n Ambystoma maculatum and A. opacum larvae become fully punctate, after stage 42, in all body regions except the posterior half of the tail, where pigment granules in melanophores in the dorsal and ventral fin and at the tail tip are completely dispersed. This tail darkening, which becomes increasingly conspicuous with advancing age, is independent of any special type of melanophore arising from caudal neural crest. Caudal and posterior trunk neural folds transplanted to flank produce populations of melanophores which become punctate in hypophysectomized hosts, while the hypophysectomized donor animals showed intense darkening of their finless tails. Posterior medullary plate, tested as a possible source for the stellate melanophores observed, gave rise to melanophores on the flank which became punctate, while the hypophysectomized donor animals showed tail darkening. On the other hand, removal of prospective tail somite tissue (stage 15) or the distal two-thirds of tailbud (stage 28) greatly reduced or eliminated darkening in the incomplete tail of hypophysectomized larvae. Transplants of these tissues produced darkened tail-like outgrowths i n hypophysectomized hosts. Both transplants and explants of tailbud skin indicate the arrival of melanoblasts in the skin at stage 33-34. Whole tailbuds, explanted at stage 28, developed a nearly complete complement of melanophores. These experiments indicate that melanophores independent of pituitary hormones for pigment dispersal originate from the same primordia as do the axial structures of the tail. (Supported by grant 0-5543-977 from N.S.F.) 273 JOSEPH THOMAS VELARDO, Yale University. Response of the uterus of the rat to estradiol178 after different periods of time after ovariectomy. Studies on estrogen-induced uterine growth in adult albino rats reveal that maximal responses are obtained with three daily doses of 1.0 to 5.0 pg estradiol-17~ when treatment is begun 7 days after ovariectomy. It thus appeared of interest to ascertain the uterine growth-promoting action of estradiol-178 after different periods of time after ovariectomy. In experiments begun 7 days after ovariectomy, and given three daily subcutaneous injections of 0.1, 1.0 and 5.0 pg estradi01-17~,the rats had uteri which averaged 238, 278 and 300 mg, respectively. Animals given 0.1 pg estradiol daily for three days starting 28, 34, 45, 60 and 450 days after ovariectomy had uteri that were 20 to 40% less responsive than those started on treatment 7 days after ovariectomy. Similar experiments utilizing 1.0 pg estradiol daily for three days commencing 28,34,45,60 and 450 days after ovariectomy produced uterine responses that were approximately 10-30% less than those given this dosage of estradiol one week after ovariectomy. Rats given the 5.0 pg estradiol treatment, again for three days, starting 28, 34, 45, 60 and 450 days postovariectomy had uteri which were 1020% less than those on the 5.0 pg treatment one week after ovariectomy. These results indicate that the uterus of the aging rat remains responsive to estradiol 18 months after ovariectomy, and that while 0.1 pg estradiol treatment is a potent uterine growth promoter in adult animals one week after ovariectomy, at least 1.0 pg daily is required to give comparable responses when the ovaries have been removed for periods of two to 18 months. (Aided by U.S.P.H.S. grant C-4773.) 387 ABSTRACTS 72 LEO VROMAN, E. TOBACH, G.TURKEWITZ and T. C. SCHNEIRLA, American Museum of Natural History. Physiological effect of preweaning manipulation in two strains of rats. (15 min.) Four groups of litters each of Wistar and Long Evans (LE) rats were subjected to graded amounts of “handling.” At weaning, half of each group was subjected to a temperature of 4°C for 90 minutes, and all were killed. The following relationships, among others, were found: weanlings which had been handled most frequently within the LE strain, and those which had been handled least within the Wistar strain, weighed least, and were the only groups in their strains to show no decrease of adrenal ascorbic acid (AAA) concentration upon exposure to cold. In the LE strain only, the least-handled group showed lowest adrenal:body weight ratio, and the AAA concentration both before and after exposure to cold paralleled the amount of early manipulation. Only in this strain was a correlation found between AAA and hematocrit when adrenal weight was held constant. (Supported by grant M-1441 from the U.S.P.H.S.) . 274 ARTHUR H. WEINTRAUB, JOHN W. WINKERT and ALBERT S. GORDON, New York University. Effects of acute hemorrhagic anemia and erythropoietin on the mitotic activity of nucleated red cells of rat femoral bone marrow. It has been suggested that erythropoietin may stimulate erythropoiesis by increasing the mitotic rate of definitive erythrocyte precursors. In the present study, colchicine was employed in the direct quantitation of the mitotic activity of marrow nucleated red cells in bled and intact rats. Significant increases in the mitotic indices (based on either total nucleated marrow cells or on total nucleated red cells) were observed in rats administered colchicine 18 and 24 hours after acute hemorrhage. Analysis of the distribution of mitotic activity indicated that increased percentages of dividing polychromatic and early orthochromatic cells were primarily responsible for the rises in mitotic index. No increase in mitotic activity was found in animals given colchicine 6 and 12 hours after bleeding. Mitotic duration was calculated to be 44-55 minutes, consistent with well established values. Turnover time from the early erythroblast to normoblast stage was calculated to be about 23 hours for the unbled controls and 12 hours for the %-hour bled group. The mitotic index based on total nucleated cells increased over control levels in animals treated with urinary erythropoietin for two days previous to colchicine injection. Since there was no corresponding increase in the mitotic index based on total nucleated red cells, the result was judged a manifestation of increased numbers of erythrocyte precursors with no increase in the mitotic rate. The effects of short term erythropoietin administration and chronic hemorrhage are under current investigation. (Supported by grant H3357 from the U.S.P.H.S.) 195 J. RICHARD WEISSENBERG, Emeritus Professor, 5225 Schuyler Street, Philadelphia 44, Pa. Further studies on the intracellular microorganism observed in the lymphocystis disease of fish. (15 min.) In abstract 268 of the preceding meeting, a microorganism consisting of a pair of small rods and often surrounded by a clear capsule was described as cell parasite in lymphocystis tumor cells. Recently, in specimens of Pkuronectes flesus, Stizostedion vitreum, Pomacanthus arcuat u s , Lepomis macrochitus carrying lymphocystis tumors, paired structures with the same morphological appearance as in the tumor cells have rather frequently been observed also in erythrocytes within their nucleus and (or) within their cytoplasm. The possibility of affinities to microorganisms described by Kirby as producing hypertrophy of nuclei of certain flagellates has not become firmer substantiated. On the other hand, the interpretation of the microorganism as representing a macrovirus appears well supported in conformity with my previous concept of the lymphocystis disease as a viral disease. The observed infection of the nucleolus, formation of colonies in the nucleus, and free distribution in the cytoplasm preceding the formation of inclusion bodies are facts known in a number of other viruses. Around a few capsulated pairs located in the cytoplasm, basophilic inclusion substance is then formed. The further development starts with multiplication of the pairs in the inclusion bodies and is followed by transformation of many rods into flaments often equipped with granules. These observations confirm the view that the rods represent the initial forms of a developmental cycle. Evidently they correspond well to the “Initialkorper” described by Prowazek ( ’ 0 5 ) in the development of the vaccinia virus. Their conspicuous arrangement in pairs makes them easily recognizable in the lymphocystis lesions. 159 JOHN H. WELSH, Harvard University. Neurohormones in molluscs. (30 min.) The neurohumors, acetylcholine (Ach), 5-hydroxytryptamine (5-HT) , dopamine and nor-adrenaline have been shown to be present in molluscan nervous systems, sometimes in relatively large amounts. For example, pelecypod ganglia contain more 5-HT than any other nerve tissue, either vertebrate or invertebrate, thus far studied, while cephalopod ganglia are rich in Ach. Enzymes required in the synthesis of these neurohumors such as choline acetylase and 5-hydroxytryptophan decarboxylase, and destructive enzymes such as choline esterase and amine oxidase are also present in molluscs. Molluscan heart and body muscle is often doubly innervated. Cardio-inhibitor nerves are usually cholinergic while the action of cardioexcitor nerves is usually mediated by 5-HT. Catechol amines may also help to regulate the heart. A body muscle such as the anterior byssus retractor of Mytilus contracts in the presence of 388 AMERICAN SOCIETY OF ZOOLOGISTS Ach and is relaxed by 5-HT. These substances are probably the normal transmitter agents for this muscle. The in viuo metabolism of neurohumors may be studied to advantage in molluscs. For example, the level of 5-HT in the nervous system may be increased by injecting 5-hydroxytryptophan and decreased by reserpine. These results are similar to those seen in the mammalian brain. Neuroglandular organs and groups of neurosecretory cells occur in various molluscs, but little is known concerning the chemical nature and physiological roles of their products. In some molluscs there appears to be a relationship between neurosecretory activity and reproductive cycles. This should be a fertile area for further study. 139 A. STANLEY WELTMAN, ARTHUR M. SACKLER and RICHARD ANDELMAN, Laboratories for Therapeutic Research, Brooklyn College of Pharmacy. Effects of thymectomy on the blood cells and platelets of male rats. (15 min.) Numerous investigations have related thymic abnormalities to myasthenia gravis, Hodgkin’s disease and lymphatic leukemia. The present study sought to determine the alterations caused by thymectomy upon the red blood cells, white blood cells, differential cell counts and platelet frequencies of young male rats. Blood samples were taken at one-month, threemonth and 6-month post-thymectomy periods. The results of studies involving thymectomized, sham-thymectomized and control animals revealed significant 3 0 4 0 % decreases in the white blood cells of thymectomized rats, such decreases were still evident at the 6-month post-thymectomy period. Analysis of the differential counts indicated however that this decrease was due primarily to a fall in the lymphocytes accompanied by relative increases in the frequencies of the neutrophil, monocyte and eosinophil cell types. Significant increases were also observed in the red blood cell and platelet counts of the thymectomized rats at the three-month post-thymectomy period. Thus, it becomes apparent that although the thymus is a small component of the lymphocytic structure, it plays an important role in blood economy, especially in lymphocytic production. Findings also point with interest to the neutrophil to monocyte to eosinophil ratios which support the premise that the thymus may be a source of monocytes. 275 NORMAN K. WESSELLS, Yale University. Initiation by thyroxine of chick epidermal differentiation in protein-free chemically defined nutrient media in vitro. Embryonic chick anterior shank skin ( 8 and 10 day) was cultured in a defined medium (Wessells, in press). Control explants in basal medium failed to differentiate normally; proliferation occurred, but cells remained in nodes or strands upon the epidermal surfaces. Conversely, explants treated with ( 1 ) Na thyroxine (Tx) (2, 20, or 200 &g/lOO ml basal medium) followed the normal ontogenetic pattern including forming birefringent tonofibrils and limited cornified areas. Treatment of other cultures with Tx at 2000 pg/ 100 ml for one hour, resulted in normal development also, to the point where some tonofibril-Wed subperiderm cells appeared. Tri-iodo-thyronine (TIT), when supplied continuously, acted like Tx as a stimulant to development. Growth hormone, alone in the basal medium, or in combination with Tx, failed to produce any observed effect on explants. Therefore, under the conditions used: (1) Tx in continuous supply causes skin to differentiate to the 16-17 day stage; ( 2 ) the reaction is concentration independent from 2 to 200 pg/lOO ml; (3) Tx functions similarly when used in massive dose for a short period; and, ( 4 ) skin differentiation will not result from treatment with growth hormone, yet can be initiated by the tri-iodo derivative of Tx. These results reinforce Bartels’ suggestion (Roux Arch., 142: 1943) that thyroxine normally initiates epidermal differentiation. Eight-day skin used here can respond to Tx or TIT from two to 4 days before the thyroid is functional in uiuo. (Willier, B. H., Analysis of Development, 1955.) No differentiation occurs, however, until the time of thyroid activity. (Supported by a pre-doctoral fellowship from the U.S.P.H.S.) 205 R. E. WHEELER and JACK COLVARD JONES, University of Maryland. The mechanics of copulation in Aedes aegypti (L.) mosquitoes. (10 min.) An actively mating male does not copulate freely with a newly emerged female partly because her terminalia are so greatly retracted and partly because she uses her metathoracic legs to prevent his clasping. If, however, the newly emerged female’s abdomen is inserted through a hole in a paper disc to block the action of her legs, and if her terminalia are extruded by gentle pressure, the male can be forced to copulate with her but insemination does not occur. In free copulation between mature adults the male seizes the terminalia of the female with claspers. As the ventrally located proctiger inserts obliquely into and blocks the vaginal orifice, the arms of the proctiger spread laterally. The mesially-grooved, crescent-shaped phallosome moves in a ventrallydirected arc and is thus in a position to penetrate the slit-like opening to the bursa copulatrix just above the upper vaginal lip. (Supported by grant RG-6021 from the U.S.P.H.S., Scientific Article Number A-866, Contribution Number 3176 of the Maryland Agricultural Experiment Station, Department of Entomology.) 48 J. R. WHITTAKER, Yale University. An in viuo analysis of tyrosinase function and melanin formation in ascidian embryos. (Introduced by Patricia F. Knight) (15 min.) Ascidian tadpoles have a melanin pigment localized in their sensory structures (otolith and ocellus). Melanin formation was observed i n detail in three species, Styela partita, Ciona intestinalis and Molgula manhattensis. Embryos of Styela, Ciona and Molgula treated M from the 2-4 cell stage onwards with 3 x 389 ABSTRACTS phenylthiourea (PTU), develop normal sensory structures which are completely non-pigmented. Since PTU inhibition is reversible, the periods in development at which tyrosinase function ceases in the sensory structures were found by removal of embryos from inhibitor at various stages. Pigmentation can occur in the otolith and ocellus of Ciona and the otolith of Styela long after hatching. The singlecelled eye rudiment of Styela loses the ability to synthesize melanin just following the time melanin normally forms ( 6 hours before hatching). Molgula, which lacks a n ocellus, loses the ability to synthesize melanin in the otolith shortly before hatching. In Styela, pigmentation activity in the nonpigmented otolith ceases or diminishes greatly with the onset of tail resorption in metamorphosis. Inducing precocious metamorphosis with neutral red causes premature loss of this synthetic ability. Cessation of pigmentation activity in the Styela eye rudiment at the time of normal first melanin synthesis cannot be reversed by tyrosine, phenylalanine, DOPA or copper. Treatment of Styela eggs with several other melanin inhibitors: diethyldithiocarbamate, thiourea and thiouracil, for a 6-hour period prior to fertilization, results in tadpoles with fully pigmented otoliths but lacking part of their eye rudiment pigment. PTU does not have this effect. Several experiments suggest that permeability factors are responsible for this phenomenon. 199 RALPH WICHTERMAN, Temple University. Survival and reproductive ability after x-irradiation in 4 species of Paramecium. (15 min) Four species of Paramecium, namely P. calkinsi, P. multimicronucleatum, P. bursaria, and P. trichium were treated as follows: counted specimens (100 or 200) were placed in air-tight, Nylon syringes ( 2 ml) and irradiated in steps of 50,000 r beginning with this dosage and extending up to at least 450,000 I. For each experiment, the 4 different species were irradiated simultaneously each in one syringe. After a given dosage, 0.2 ml of fluid containing a precisely countable number of specimens-commonly less than 10-were expressed from a syringe for isolation into spot plates for the establishment of survival-reproduction curves. P. trichium, which is the most radiosensitive, recovers and reproduces only at the lower dosages. On the other hand, P. calkinsi from sea-water i s the most radioresistant showing relatively fast recovery and reproductive ability even after fairly high dosages. Immobilized irradiated paramecia may remain seemingly dead for as long as 24 hours. Like dead ones, they settle on the bottom of the container and do not ingest food. Active cyclosis and ciliary movement are not apparent. Recovery in such forms begins by feeble ciliary activity, then a gradual and slow gliding of the organisms on the bottom of the dish without the characteristic spiral swimming which occurs later after major recovery from irradiation effects. The data show that while reproduction may be blocked temporarily by irradiation longer than 24 hours, there is usually a gradually increased re- productive rate so that paramecia from large mass cultures-the progeny of irradiated specimenshave a reproductive rate comparable to the unirradiated controls. (Part of a project aided by a grant from the Committee on Research, Temple University, and contract NR 104475 between the Office of Naval Research, Department of the Navy, and Temple University.) 276 CHARLES G. WILBER and FREDERICK N. SUDAK, Loyola College and Albert Einstein College of Medicine. Circulatory responses of Elasmobranchs to hemorrhage. Specimens of the smooth dogfish, Mustelus canis, and of the spiny dogfish, Squalus acanthius, were pithed and the ventral aorta exposed. Blood pressure was recorded through a catheter in the aorta leading to a pressure transducer recording system. Electric recording of movement of the branchial muscles gave respiratory rates. Various amounts of blood ( 1 to 10 ml) were removed from the fish via the caudal vein; the effect of removal on heart rate, respiratory rate, and blood pressure was observed. The blood was then reinfused and comparable observations were made. Heart and respiratory rates were unchanged. The circulatory system in each species behaved essentially as a simple pressure-volume container. It was found that the mean blood pressure (M) is related to systolic (S) and diastolic (D) pressures as follows: M = ( S D) 0.45. The response to hemorrhage can be expressed: for Mustelus 100/ y=4.2+0.35x, r=0.936; for Squalus 1OO/y=6+ 0.3x, r = 0.898; where y is mean blood pressure in ml Hg and x is blood deficit in milliliters. Early anatomical studies on Elasmobranchs fail to reveal vasoconstrictive nerves associated with the blood vessels. The present results are in accord with such observations. There is no obvious vasomotor compensation for blood loss in Mustelus or Squalus. If blood is removed from the smooth or the spiny dogfish, blood pressure falls. As blood is returned, blood pressure rises. The effects of various drugs on response to hemorrhage in these species are being investigated. (Supported in part by grant MY-3235 and H-3563(Cl) from the U.S.P.H.S.) 223 JOHN W. WINKERT, ALBERT S. GORDON and GEORGE CALVOSA, New York University. Chromatographic separation of human urinary erythropoietic stimulating factor (ESF). (15 min.) Urine samples from Thalassemia subjects with hemoglobin values of 4 gm% or less were filtered and screened for ESF activity by injection into 170-220 g m female rats. When 5 daily 3 ml subcutaneous injections of a sample increased reticulocyte counts by 300400% and hematocrit values by 15-25% it was selected for further refinement. ESF was precipitated from urine with 4 volumes of methanol, ethanol, propanol or acetone at - 10'C. Methanol afforded the highest yield of ESF while propanol and acetone were least effective. Ethanol precipitated preparations were dissolved in a minimum volume of 0.16 M NaCl and + 390 A M E R I C A N SOCIETY OF ZOOLOGISTS dialyzed 4 days at 5°C against 0.005 M Na2HPOl (pH 7.3). One half gram of DEAE cellulose was mixed with every 100 ml of dialysate and removed by centrifugation. ESF was eluted from each DEAE cellulose sediment with 50, 25, and 25 ml of 0.12 M NaC1-0.005 M Na2HP04 (pH 7:3). The combined eluates were dialyzed agamst 0.005 M NazHP04 (pH 7.3) and applied to a 1 x 6 cm DEAE cellulose column previously washed with 0.16 M NaCl-0.005 M Na2HP04 (pH 7.3) and equilibrated with 0.005 M Na2HP04 (pH 7.3). Gradient elution at pH 7.3 from 0.005 M NasHPO, to 0.005 M NazHP04-0.16 M NaCl resulted i n two successive elution peaks absorbing maximally at 278 mp. The two peaks emerging between 0.10 M and 0.12 M NaCl contained approximately 100 and 50 cobalt units of ESF activity per milligram of protein respectively. (Supported by grant H-3357 from the U.S.P.H.S.) meable cuticle act as receptor organs which respond to the temperature changes resulting from different rates of evaporation. Behavior of the mite is such that the receptor organs seem to function in the same way as do the mammalian temperature receptors described by Zotterman (Ann.Rev. Physiol., 15: 357-372, 1953) in which the time rate of change is the important factor. Activity patterns, behavior, and ecology support the possibility that humidity responses i n this animal function i n such things as feeding behavior and fecundity rather than in the reduction of water loss, as is the case in most terrestrial arthropods. 92 ALBERT WOLFSON, Northwestern University. Mechanism of photoperiodic regulation of reproductive and migratory rhythmicity in birds. (15 min.) Extensive studies of the role of day length in 145 HOWARD E. WINN and JOSEPH MARSHALL, the regulation of reproduction and vernal migraUniversity of Maryland. Sound production of tion have shown that the annual periodicity of these events is regulated in two phases-a presquirrelfishes. (15 min.) paratory phase and a progressive phase. To The organ of sound production, hearing, be- elucidate the mechanisms involved i n these havioral circumstances under which two types of phases, studies have been made under various sound were produced, die1 variations of sound photoperiodic schedules of the hypothalamo-hyproduction and reactions toward various sounds pophyseal system, the role of gonadotropic horwere studied. All field results were duplicated in mones, and the role of testosterone. Observations the laboratory. The fish basically produces two on the hypothalamo-hypophyseal system included types of sounds, one under low stimulation to- (a) quantitative determinations of acid phoswards familiar individuals and another with phatase in the region of the supraoptic nucleus, greater stimulation towards unfamiliar discon- the region of the median eminence, the adenotinuous moving objects such as the moray eel. hypophysis, and the neurohypophysis and ( b ) This results in increased escape, attentive and studies of the Gomori-positive material in the investigative behavior of the squirrelfish. Die1 supraoptic nucleus and median eminence. variations i n the production of the two sounds During the progressive phase, the daily photoand in the locomotory activity patterns differ period induces release of neurosecretory material signi5cantly. The air bladder both produces which i n turn stimulates the gonadotropic acsound and transmits sound vibrations to the tivity of the adenohypophysis. The rate of reinner ear which presents a unique problem lease and the duration of reproductive activity in the physiology of hearing. The range of hearare a function of the duration of the daily photoing is greater than that of most ostariophysid period. After the gonads have reached almost fishes (below 300 up to 8,000-9,000 cps). (Sup- maximum size they may be maintained by testosported by the Office of Naval Research, N.R. terone alone. Ultimately, the gonads regress, 104-489.) but the cause is not known. During regression, 202 administration of gonadotropins from pregnant PAUL W. WINSTON, University of Colorado. A mare serum induces reactivation. possible humidity receptor mechanism in the Before another period of reproductive activity clover mite, Bryobiu pruetiosa Koch. (10 min.) or vernal migratory physiology can occur, the When normal clover mites are subjected to a preparatory phase must be completed. It requires choice of two humidities in small tubes, a signifi- exposure for approximately 6 weeks to daily cant majority is always to be found in the lower uninterrupted dark periods of at least 12 hours humidity. Forty-six relative humidity combina- duration. Without this treatment, the neurosecretions and over 100,000 position records at 25OC tory material cannot be released from the median have shown no deviation from this whether the eminence i n sufficient amounts to induce a m e r e n c e is two or 90 percentage points. The gonadal response. There appears to be a daily cycle of response to response is to the difference between the two humidities not to relative humidity, saturation the periods of light and darkness whose net deficit, nor to any particular part of the humidity effect is a particular rate of response for the range. With a given difference, the response is light-dependent or dark-dependent reactions deessentially the same strength i n all parts of the pending on the season of the year or the sequence range. It is postulated that the response of these in the cycle. The annual rhythmicity is induced mites is to areas of increasing rates of evapora- by these daily reactions. The timing of vernal tion; thus the steeper the humidity gradient (the migration and reproduction is controlled largely greater the percentage difference) the stronger is by the dark-dependent reaction which occurs during the previous autumn. (Supported by a grant the s t i m u l u s . It is possible that small areas of high permeability i n an otherwise almost imper- from N.S.F.) ABSTRACTS 177 MARIA de ISSEKUTZ WOLSKY and ALEXANDER WOLSKY, Manhattanville College and Fordham University. The effect of a carcinostatic antimetabolite on the development of sea urchin eggs. (15 min.) The sodium salt of N-dichloroacetyl dl serine (“Frost-T-9045”, see Levi, Blondal and Lozinski, Science, 131: 666, 1960) was tested on eggs of Paracentootus lividus. In a concentration of 200 mg% it produced serious disturbances in development. (Lower concentrations had weaker effects, 1 mg% had none.) In most cases gastrulation was not completed and development often arrested in the blastula stage. The effect was stronger when the treatment was started just before fertilization than immediately afterwards. Changes of egg permeability at fertilization are believed to be responsible for this difference. If the treatment is stopped in time, recovery occurs and in most cases normal plutei are obtained. Pre-treatment of sperm for several hours has no effect on subsequent development. Similar pre-treatment of unfertilized eggs has a very slight effect, manifested mainly in a time lag in development. Treatment started in later developmental stages resulted only in slight effects on growth, especially of the arms. A conspicuous effect was shown on ciliary movements, which were slowed or stopped altogether in most cases, while the controls were swimming vigorously. It is concluded that N-dichloroacetyl dl serine is not a specific antimitotic agent but interferes with protein synthesis in general. (Work supported by U.S.P.H.S. research grant RG-6713 and by Manhattanville College; carried out at Station Biologique Roscoff (University of Paris, France.) 113 PAULINE J. WOOD, University of Washington. Histodifferentiation in the palate of the human embryo. (15 min.) As a basis for investigations of developmental mechanisms in the palate region, a study of normal growth and differentiation of the human palate has been undertaken. The critical period for palate formation in the human lies between 8 and 10 weeks of the gestation period. During this interval the shelves elevate and fuse, and ossification in the palatine processes, already perceptible at 8 weeks, intensifies. The ensuing weeks witness further differentiation at the cell and tissue level, although differentiation is apparently not yet complete at birth. 391 A series of frontal sections was prepared on the palates of formalin-fixed human embryos and fetuses of 6 through 20 weeks. At least three embryos were sectioned for each week of the period 6 through 10 weeks; thereafter, fetuses of 12, 14, 16, 18 and 20 weeks were prepared as above. Additional sections were obtained from occasional fresh specimens aged 5 through 9 months. Routine staining with hematoxylin and eosin and Mallory’s triple stain was carried out. In addition, selected sections were tested for the presence of collagen fibers, elastic fibers, lipids, nerve fibers and keratohyalin. Development of these several components, as well as certain morphological features, will be discussed. (Supported by grant D(C1)-910 from the U.S.P.H.S.) 215 LEONARD G. WORLEY and BETTY HERSHENOV, Brooklyn College. Electron microscopy of the elaboration of protein yolk by the Golgi complex during the early development of Crepidula. (15 min.) In electron micrographs of the veliger larva the following stages in the Golgi cycle can be identified : homogeneous Golgi droplets (“Praesubstanz” of Hirsch); simple and compound Golgi vesicles (“Systeme” and “Polysysteme” of Hirsch) ;pycnotic Golgi bodies (Golgi “Reste” of Hirsch; Gold “remnants” of spermatogenesis). Protein yolk spheres, arising as the chromophobic components of the Golgi vesicles, are completely and intimately invested by chromophilic Golgi envelopes throughout their growth period. Upon their attainment of full growth the chromophilic component withdraws and then lies in a collapsed condition at the side of the mature yolk sphere. Electron micrographs fully substantiate the vital dye studies of Worley and Worley (’43) in Navanax except that an elaboration of “fatty” yolk has not been noted and indeed there appears to be very little ‘Yatty” yolk in Crepidula. The Golgi substance presents an obvious lamellated structure at no stage in the secretory process, but the identification of the material as Golgi i s fully confirmed by phase contrast and vitally-stained living material as well as by fixed preparations for light microscopy and by hypertonic treatment of vitally-stained specimens. These results suggest that in these and perhaps in all animal cells the function of the Golgi “apparatus” is the constant building up of formed energy reserves from the raw nutritive substances present in the cytoplasm.