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Blood-Cell formation in the horned toad phrynosoma solare.

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BLOOD-CELL FORMATION I N THE HORNED TOAD,
PHRYNOSOMA SOLARE
H. E. JORDAN AND C. C. SPEIDEL
Medical School, University of Virginia
FOUR PMTES
( FORTY-ONE
FIGURES)
INTRODUCTION
The horned toad affords an exceptionally favorable material for the study of erythrocyte formation in the reptilian
spleen. Though granulocytes also take origin in the spleen,
their number is never large, contrary to conditions in the
spleen of the turtle, where occur enormous numbers of both
basophilic and eosinophilic granulocytes. The marrow of
the long bones of Phrynosoma is moderately active in granulocytopoiesis. In our material there is only very meager
erythrocytopoietic activity in the marrow, if, indeed, it occurs
at all. The spleen is also the chief locus of thrombocyte and
monocyte formation.
While the spleen of the horned toad resembles that of the
frog, especially in the occurrence of quiescent fibrous nodules
(figs. 3 and 5) correlated with final phases of hemocytopoietic
activity, it differs in that the cells of the sinuses are generally
much less densely crowded (figs. 1 and 2)-a circumstance
which facilitates microscopical study. This more favorable
condition is, however, neutralized to some extent by the fact
that the cells are considerably smaller than those of most
amphibia and reptiles. On the credit side for this tissue may
be placed the fact that the splenic vein, in contrast to the
artery, contains the same cells as the intrasplenic sinuses,
namely, all transition stages between the ancestral lymphocytes and definitive erythrocytes, monocytes, granulocytes,
77
T H E AMERICAN JOURKAL OF ANATOMY, VOL. 43, NO. 1
78
H. E. JORDAN AND C. C. SPEIDEL
and thrombocytes. Since 'these cells are relatively widely
scattered in the blood of the splenic vein, the developmental
series may be readily traced.
Contrary to the conditions in the salamander, the subcapsular perihepatic region is devoid of granulocytopoietic
capacity. Such could not be stimulated even 'by splenectomy,
at least after an interval of seventy-four days. Nor could
the theoretically potential hemopoietic tissue of the intertubular stroma of the kidney be aroused to compensatory
activity by splenectomy in our small series. I n view of the
relatively meager splenic and myeloid granulocytopoietic
activity, the absence of other foci of granulocytopoiesis seems
remarkable. This fact, compared with conditions in turtles,
where splenic granulocytes are extremely numerous, would
seem to point to some fundamental differences in the metabolic or protective requirements in these two groups of
reptiles.
I n the evolution of blood-forming tissues in vertebrates the
reptiles occupy an important transition level. I n amphibians
generally the spleen is also the chief locus of red-cell production. The spleen is likewise the main source of lymphocyte
origin. I n birds erythrocytopoiesis is almost completely
shifted to the bone marrow, and lymph nodes occur here
for the first time in vertebrates. I n the intermediate phylum
of the reptiles the shift in the direction of the avian complex
of hemocytopoietic tissues has been made only to the extent
that the bone marrow plays a slightly greater r81e. I n
Phrynosoma the complete hemocytogenetic process can be
studied under very favorable conditions within the limits of
the spleen. This seems the more remarkable when one considers the small size of the spleen. I n proportion to the size
of the animal the spleen is exceptionally small, never over
5 mm. in diameter and frequently only half that size. Possibly this is correlated with the relatively sluggish habits
of the animal.
Another matter of paramount importance concerns the
presence of a considerable number of so-called plasma cells
BLOOD-CELL FORMATION I N THE HORNED TOAD
79
and cells with Russell bodies in the spleen of Phrynosoma.
The evidence here indicates that plasma cells are degenerating hemoblasts, sometimes culminating in terminal stages as
cells with Russell bodies. Where blood formation is as active
as it is in certain regions of certain of these spleens, it would
seem to be well within the range of legitimate expectation
that a certain number of young erythroblasts or granuloblasts
should mature imperfectly and end as cell monsters.
MATERIAL AND METHOD
The material of this investigation consists of the spleens
of fifteen individuals, comprising both sexes, of various sizes.
The spleens were fixed in the Zenker-formol mixture of Helly,
embedded in paraffin, sectioned at 7 p and stained with the
eosin-azur combination of Giemsa. F o r the material we are
indebted to the kindness of Dr. Donne11 B. Young, formerly
Professor of Zoology at the University of Arizona.
DESCRIPTION
No correlation between size of spleen and sex or size of
individual was noted in our specimens. The smallest spleens,
approximately 1.5 mm. in diameter, contained, in general, the
largest number of fibrous nodules and the least internodular
parenchyma (fig. 5). The largest spleens, approximately
5 mm. by 1 mm., were hemopoietically the most active, with
fewer and smaller fibrous nodules and wider sinuses.
Figure 1 shows a median longitudinal section of one of
the largest spleens. It is enveloped by a delicate fibrous
capsule continuous with similar trabeculae which effect a
more or less distinct lobulation. At the hilum can be seen a
large thin-walled splenic vein and a small artery with robust
wall. The splenic tissue is divisible into three constituents :
fibrous nodules, parenchymal cords, and sinuses. Occasional
irregular aggregations of small lymphocytes suggest the
splenic nodules of mammalian spleens. Typical nodules occur
also in the spleen of the turtle; but the spleen of the horned
toad resembles more closely that of the frog.
80
H. E. JORDAN AND C. C. SPEIDEL
The fibrous nodules are relatively few in number and small
in size in the more active spleens (figs. 1,2, 3, 4,and 6). I n
general, these are deeply located along the axis of the spleen.
They contain an arteriole and a more peripheral mesh of
capillaries. The fibrous tissue includes relatively few cells,
predominantly of the stellate and lamellar varieties. Lymphocytes are sparse. There may be a few plasma cells (figs. 35
to 38), monocytes (figs. 27, 28), Russell-body cells (figs. 39
to 41), and an occasional abortive eosinophilic granulocyte
with basophilic granules and a n irregular chromatic nucleus
(figs. 29 to 31). The parenchymal cords consist essentially of
lymphocytes, the small variety predominating. I n addition,
there occur also various early transition stages between these
cells and definitive blood cells, and especially between lymphocytes and thrombocytes. Granulocytes occur only in small
numbers. The sinuses contain the later transition stages between large and small lymphocytes and erythrocytes and
thrombocytes, respectively, and all types of the definitive
blood cells.
A somewhat later stage in the splenic hemocytopoietic cycle
is represented in figure 2. Here the sinuses are relatively
much wider, there occurs also a distinct peripheral sinus;
and the cords are reciprocally less extensive and distinct and
the fibrous nodules considerably larger. Figure 3 represents
a still later stage, while figures 4 and 6 represent slightly
earlier stages in the cycle as compared with figure 2. The
hemocytopoietic cycle has practically culminated in the spleen
shown in figure 5. Here the fibrous nodules occupy by f a r
the greater portion of the spleen. The spleen of figure 7
represents the beginning of a new cycle of hemocytopoietic
activity. The fibrous nodules persist as prominent, very
irregular masses of reticulum, in some of which the arteriole
appears conspicuously. The peripheral portions of these
nodules represent original cords from which the lymphocytes
have migrated. These extensions contain the terminal arterioles and capillaries (fig. 9 ) . The internodular areas are
filled with blood cells, including predominantly definitive
BLOOD-CELL FORMATION I N THE HORNED TOAD
81
erythrocytes. Spleens of this stage contain also many
atrophic and abortive cells, including plasma cells (figs. 35
to 38) and cells with Russell bodies (figs. 39 to 41).
The new hemocytopoietic cycle begins with activity at the
border of these nodules (fig. 8). Here large and small
lymphocytes separate from the reticular syncytium. The
large lymphocytes proliferate by mitosis. Smaller lymphocytes may grow to become larger varieties. At the height
of this progress of lymphocyte genesis and multiplication
the earlier fibrous nodules (fig. 9) have become cellular (figs.
8 and 10) and have the typical structure and appearance of
splenic nodules. Their lymphocytes are swept into the
splenic sinuses, meanwhile entering the early stages of differentiation into the several varieties of definitive blood cells.
A certain number of these mature abnormally and pass
through plasma-cell stages to end largely in cells with Russell
bodies. There appears no evidence suggesting origin of redcell ancestors from endothelium.
ERY THROCY TOPOIESIS
The ancestor of the red cell is the medium-sized lymphocyte (fig. 14). This cell occurs both in the spleen and the
general circulation. Here the lymphocyte is the hemoblast.
It is a spherical cell, with relatively large nucleus. The
meager envelope of cytoplasm is strongly basophilic. The
nucleus contains one or several nucleoli. This erythrocytogenic lymphocyte traces its ancestry back t o an irregular
mesenchymal cell with vesicular nucleus (fig. 11). The intermediate stages are characterized by a nucleus whose originally delicate reticulum becomes progressively coarser, an
acidophilic nucleolus which grows progressively more chromatic, and a cytoplasm which becomes progressively more
basophilic. The medium-sized lymphocyte (fig. 14) differentiates into an erythrocyte (figs. 20 to 2 2 ) . In the intervening stages the shape of the cells changes to a spindle form,
the nucleus becomes progressively smaller, more oval and
dense, and the cytoplasm loses its basophily with the elabora-
82
H. E. JORDAN AND C. C. SPEIDEL
tion of hemoglobin (figs. 15 to 19). ' At the intermediate phase
the cytoplasm of the erythroblast is polychromatophilic (fig.
18). The maturation of nucleus and cytoplasm is not necessarily a closely correlated process (compare fig. 15 with 18,
and 19 with 20). Erythroblasts multiply generally by mitosis.
Proliferation may occur apparently also to some extent by
the amitotic mode (fig. 23).
THROMBOCY T O P O I E S I S
The thrombocytes develop from small lymphocytes (figs. 24
to 26). The thromboblast is characterized by a vesicular nucleus with achromatic nucleolus. The meager rim of cytoplasm is deeply basophilic. The nucleus becomes progressively denser and more elongate, and the cytoplasm loses its
deep basophily, giving a pink color reaction with the Giemsa
stain. I n smear preparations stained with Wright's stain a
rosette of azurophilic granules is a conspicuous characteristic
of these cells.
MONOCY T O P O I E S I S
The monocytes (figs. 27, 28) also trace their ancestry to
lymphocytes, perhaps in part directly t o the reticular stroma
(fig. 27). Their nucleus resembles that of the typical lymphocyte, but they possess a more massive envelope of basophilic
cytoplasm. The cytoplasm invariably contains a more lightly
staining circular area, in close proximity to the nucleus.
While this area, no doubt, includes the centrosome and represents archoplasm, as it appears in stained sections it is
largely a fixation (coagulation) artifact, the result of a difference in consistency in the cytoplasm of the two areas.
The presence of short blunt pseudopods and the irregularity
of contour indicate considerable ameboid activity.
That these cells may become extremely active under special
conditions has already been pointed out in a separate communication (Jordan and Speidel, '28). They may arise also
from other sources than the spleen. Under the stimulus of
hemorrhage into the peritoneal cavity following splenectomy,
the monocytes appeared in great numbers in the hepatic per-
BLOOD-CELL FORMATION I N THE HORNED TOAD
83
itoneum. Some migrated to this region, but others arose in
loco from the connective tissue of the hepatic capsule, from
peritoneal endothelium, and from lymphocytes.
GRANULOCYTOPOIESIS
The granulocytes include eosinophils (figs. 32 and 33), basophils (figs. 29 to 31), and possibly neutrophils (fig. 34).
Their number in the horned toad is relatively small as compared, for example, with the turtle. The history of the eosinophi1 is clear. These cells develop from lymphocytes; to some
extent more directly from the reticular cells (compare figs.
32 and 12). As the granules increase in number the nucleus
becomes polymorphous and moves to one pole (fig. 33). Frequently, the nucleus consists definitely of two widely separated lobes, interconnected by a delicate chromatic strand.
The initial granules, while less acidophilic, with a purplish
tinge, in this material have never been seen in the condition
of orthobasophily.
The condition of the basophilic leucocytes is of special interest, because of the possibility that they may represent
abortive eosinophils in which the granules failed to ripen
properly. Coincidently with the degenerative process in the
granules, the nucleus also passes through regressive stages.
No basophils could be found with a nucleus like that of a
young eosinophil (fig. 32). The youngest nucleus is already
smaller, more spheroidal, and more compact, with a coarse
chromatic reticulum. This nucleus may still retain a nucleolus. As the granules become more irregular and more
variable in size and stain more deeply, the nucleus becomes
more dense and irregular (fig. 31). However, the nucleus
does not come to resemble that of the definitive eosinophil
either in shape or structure. It is a compact, deeply staining,
coarsely granular, or almost homogeneous body. It has all
the marks of a dying nucleus.
These observations become particularly significant when
coupled with the discovery that in turtles there occur granulocytes, each of which contains a mixture of basophilic and
84
H. E. J O R D A N A N D C. C. S P E I D E L
eosinophilic granules. These have been seen in the thymus
of the common box-turtle, Terrapene (Cistudo) Carolina.
They are interpreted as representing a transition stage from
basophilic leucocytes to eosinophils, with the granules in different stages of the ripening process. I n the light of these
data, the condition of the basophils in the horned toad strongly
suggests an interpretation in terms of abortive eosinophils
in which the granules failed to ripen properly.
There appears very sparingly a type of cell resembling
somewhat a small lymphocyte, except that the cytoplasm is
more extensive. The vesicular nucleus is characterized by
larger angular blocks of chromatin-a
condition by some
regarded as diagnostic of a plasma cell. The cytoplasm contains minute pinkish granules (fig. 34). This cell corresponds
closely to that described by Alder and Huber ('23) as a
neutrophilic granulocyte in Lacerta and Tarentola. Its
significance remains uncertain. Jordan and Flippin ( '11),
in their study of the blood cells of certain chelonians, were
unable to identify true neutrophils.
PLASMA CELLS AND CELLS WITlF RUSSELL BODIES
Plasma cells are derived from lymphocytes. Their salient
characteristic is a vacuolated condition of the cytoplasm.
There may be a single large vacuole (figs. 35, 36) or numerous vacuoles of various sizes (figs. 37, 38). When the
single vacuole is of smaller size, as in figure 35, the plasma
cell resembles a monocyte (figs. 27, 28). However, the cytoplasm is generally more deeply basophilic, the cell is generally larger and more oval in shape, and the nuclear chromatin is commonly distributed in larger angular masses. The
nucleus is generally located toward one of the poles. A closely
graded series may be traced from lymphocytes like those
illustrated in figures 13 and 14, through earlier stages like
those of figures 35 and 36, to older stages like those of
figures 37 and 38. Plasma cells apparently represent regressive forms of lymphocytes. Moreover, the series may be
continued into the group of cells with the so-called Russell
BLOOD-CELL FORMATION IN T H E HORNED TOAD
85
bodies. Figure 39 represents an early form of the latter cell.
The nucleus has become pushed to one pole and compressed
into an oval form. The cytoplasm contains two pink-staining
globules. These globules apparently represent the ‘vacuoles’
of the plasma cells, the ‘mucoid’ content of which has now
become concentrated into a more viscid ‘hyaline ’ condition.
Figure 40 represents a much later stage where practically all
of the cytoplasm has become displaced by the hyaline globules. I n figure 41 is shown a subterminal condition in which
the nucleus has almost disappeared under pressure, and the
many smaller original globules have become fused into two
large hyaline vesicles. The interpretation that is most forcibly suggested from a study of these cells is one in terms of
degenerative stages in abortive hemoblasts.
DISCUSSION
The point of special interest and value in this study of
hemocytopoiesis in the horned toad concerns the identity of
lymphocyte and hemoblast. The lymphocyte of the splenic
sinuses or the general circulation may differentiate into an
erythrocyte. The initial impulse to granulocytopoiesis is apparently received only outside the endothelium-lined channels; but the later steps may be completed within the venous
circulation. I n the proximal end of the splenic vein occur
great numbers of transition stages between lymphocytes and
erythrocytes. Such do not occur in the splenic artery. The
horned toad, like other reptiles and like amphibia, has no
other hemoblast than the lymphocyte. Sojourn in the slowly
moving blood current of the splenic sinuses, with their relatively high concentration of carbon dioxide, determines a
hemoglobin-elaborating bias. We have here the very strongest sort of evidence in support of the monophyletic theory
of blood-cell origin. If the lymphocyte may here differentiate
into an erythrocyte within the sinuses of the spleen, it seems
reasonable to believe that it may have a similar history within
the bone marrow of birds and mammals, where structural and
vascular conditions are very similar.
86
H. E. JORDAN AND C. C. SPEIDEL
Alder and Huber ( '23) have described conditions identical
with those of horned toad in the spleens of certain reptiles
and amphibia. However, they resolve any conflict between
their evidence and the polyphyletic theory of blood-cell origin
by claiming that the hemoblast of amphibia and reptiles is not
a true lymphocyte ; that lymphocytes occur first only in birds
and mammals. I n view of the cytologic identity between the
so-called hemoblasts of amphibia and reptiles and the lymphocytes of birds and mammals, such conclusion is not warranted.
While lymph nodes are lacking below birds, other lymphoid
masses, including spleen, thymus, and the adenoid areas of
the intestinal wall produce typical lymphocytes in all the
vertebrates beginning with fishes. It is only when bone marrow occurs in considerable amounts, as in birds and mammals,
that the original erythrocytogenic function of the spleen
becomes shifted to the myeloid tissue. Here the red-cell
ancestor, the hemoblast, is a lymphocyte-like cell, and may
either arise in situ or be filtered from the blood stream after
an origin in distant lymphoid tissues, either spleen or lymph
nodes. That even the small lymphocyte may function as a
red-cell ancestor is proved by its history in certain modified
lymph nodes of the rabbit and dog (Jordan, '26 b), and by
the experimental evidence supplied by Maximow ( '07) in the
case of the kidney of the rabbit following vasoligation. By
this procedure Maximow stimulated the production of red
marrow in a tissue which ordinarily lacks local lymphocytes.
The lymphocytes of the stagnating blood in the enlarged
lumens of the renal capillaries hypertrophied and became
transformed into hemoblasts. These cells in turn continued
differentiation into erythroblasts, granuloblasts, and megakaryocytes.
On the basis of his study of blood formation in the living
chick blastoderm, Sugiyama ( '26) derives the thromboblasts
from 'megaloblasts.' This is in sharp disagreement with
Maximow ( '27), who studied thrombocytogenesis in the chick
in vitro. He describes the direct transformation of lymphocytes into thrombocytes. Dantschakoff ( '10) observed the
BLOOD-CELL FORMATION I&
THE HORNED TOAD
87
origin of thrombocytes from small lymphocytes in snake
embryos. I n certain chelonians, also, Jordan and Flippin
( ’13) described a similar origin of thrombocytes.
I n our material the thromboblast is a small lymphocyte.
The definitive thrombocyte, no doubt intimately related to
thrombus formation, is functionally a normal cell. It appears
to us that its origin is correlated with the small amount of
cytoplasm in proportion to nucleus in the ancestral lymphocyte. If the process of differentiation starts in such a lymphocyte, the result is a thrombocyte, the supposition being that
the cytoplasm is inadequate in mass for the elaboration of
hemoglobin. If, however, the lymphocyte grows in size and
increases its cytoplasmic bulk before differentiation sets in,
it becomes capable of giving rise to other types of blood cells
than thrombocytes. Thus, the thrombocyte is derived from
the lymphocyte which starts its differentiation process while
it possesses a very meager cytoplasmic envelope. Sugiyama’s
conclusion that thrombocytes are independent cell elements,
derivatives of a distinct ancestor, is hardly consistent with
his claim of ‘megaloblast’ ancestry. Such ancestry relates
the thrombocyte even more closely to the erythrocyte than
our conclusion of derivation from a hemoblast too small to
support a hemoglobin-elaborating activity.
The basophilic granulocytes call f o r special consideration.
Conditions in the spleen and circulation strongly support our
previous hypothesis (Jordan and Speidel, ’23), which regards
the cells with metachromatically basophilic granules as abortive eosinophils. As pointed out in the introduction, eosinophils are relatively rare in Phrynosoma. Coincidently, basophils are also rare. These latter cells mostly have clearly
degenerate nuclei (fig. 31). The invariable association here
of deeply staining, compact, coarsely granular nuclei, with
metachromatic angular non-uniform cytoplasmic granules at
least strongly suggests a significance of abortive maturation.
Plasma cells are fairly numerous in the splenic sinuses of
Phrynosoma, especially in the very active and in the exhausted spleens. The simpler forms, such with a single light-
88
H. E. JORDAN AND C. C. SPEIDEL
staining circular area or ‘vacuole,’ show clearly a derivation
from lymphocytes. Their later history suggests degeneration conditions. It is to be expected that where hemocytopoiesis is very active, or maintained under conditions of
exhaustion, many of the ancestral lymphocytes, the hemoblasts, should develop abnormally. Such cells, known also as
‘plasmoidocytes ’ (Maximow, ’17) and as ‘Turk’s irritation
cells’ are very common in inflammatory areas in mammals.
They have rarely been described in cold-blooded vertebrates.
Downey ( ,ll), however, described them in some detail in
the ganoid fish Polyodon, in certain frogs, and in the garter
snake. He derives them from all types of lymphoid cells,
chiefly of histogenous origin. He interprets them as secretory cells. Maximow likewise derives these cells from
lymphocytes, but regards them as always degenerate.
I n a recent contribution, Maximow (’27, p. 10) seems to
identify plasma cells of inflammatory regions with ‘polyblasts. ’ Thus, according to Maximow’s conception, certain
plasma cells, under certain conditions, may retain the ability
to differentiate further. This is significant in respect of the
possible misinterpretation of certain hypertrophied lymphocytes of lymph nodes under certain conditions (Jordan, ’26 a).
These cells have some of the marks of so-called plasma cells,
but may differentiate to a greater or less extent along the
erythroblastic or granuloblastic routes. Maximow identified
his polyblast with the histiocyte and macrophage. He stresses
the point of a ‘distinct morphologic conception,’ especially
as concerns the monocyte and polyblast (macrophage). At
the same time he admits the possibility of direct transformation of a lymphocyte into a monocyte, and of the monocyte
into a macrophage.
According t o Schridde ( ’05), plasma cells may elaborate
also neutrophilic, eosinophilic, and metachromatic basophilic
granules. Dubreuil and Favre ( ’21) also describe plasma
cells with eosinophilic granules. Most workers interpret the
cells with the so-called ‘Russell fuchsin-bodies ’ as later stages
in the development (or regression) of plasma cells. Downey
BLOOD-CELL FORMATION IN THE HORNED TOAD
89
regards the Russell bodies as a thickening of the normal secretion of plasma cells. Dubreuil and Favre describe plasma
cells with a mixture of eosinophilic granules and Russell
bodies ; also plasma cells with basophilic granules. They
claim that plasma cells with neutrophilic granules do not
occur. The neutrophilic granulocytes of Schridde they interpret as a subvariety of plasma cells with oxyphilic granules.
Russell bodies, according to their view, are anomalous
eosinophilic granules, either in globule, granule, or crystalloid form. The function of Russell bodies remains unknown.
They are destined only to disappear, either by degeneration
o r phagocytosis. They were originally regarded as the
causative organism of cancer.
The work of Keasbey may throw considerable light on the
significance of the Russell bodies. She studied the so-called
' Sch~llenleukocyten~
of Weill ( '19), found abundantly in the
mucosa of the abomasum of the sheep. These cells are very
similar, probably identical with Dubreuil and Favre 's plasma
cells with eosinophilic granules and Russell bodies. She applied various microchemical tests for hemoglobin to these
granules and reports a positive reaction. If these reactions
actually reveal the presence of hemoglobin in the form of
granules and globules, then these plasma cells would seem
to be anomalous normoblasts. Furthermore, if the granules
of the cells described by Dubreuil and Favre are actually true
eosinophilic granules, and the 'Russell bodies of these same
cells actually contain a trace of hemoglobin, as the work of
Keasbey suggests, then we may be dealing with modified
hemoblasts in which both erythrocytic and granulocytic potentialities are partially expressed, resulting in a hybrid cell.
This line of evidence closely connects a plasma cell with the
hemoblast. I n other words, plasma cells may be abortive
erythroblasts and granuloblasts.
The importance of these conclusions inheres in their bearing on the interpretation of certain cells described by Mottram ( '23), and by Jordan ('as),and by Dawson ('27) in
certain lymph nodes. These cells have been regarded as
90
H. E. JORDAN AND C. C. SPEIDEL
plasma cells by some investigators, e.g., Macmillan ( ’28).
Since they lack the complete complex of typical plasma-cell
characters, Maximow (’17) has designated them as ‘plasmoidocytes.’ Mottram ( ’23) describes them as closely resembling “cells which give rise to red cells in the spleen,
and very occasionally have been seen having the same function in the iliac lymph gland.’’ Mottram thought he was able
to produce them by radium irradiation. Dawson thought he
found x-ray irradiation effective in the dog. However, Jordan
(’26 b) finds them in the lymph nodes of apparently normal
unirradiated dogs, rabbits, and guinea-pigs. Jordan and
Dawson both regard these cells as lymphoid hemoblasts. Both
describe a small number of these cells as differentiating into
normoblasts. Associated with these cells are various proportions of more typical plasma cells with vacuolated cytoplasm,
and a few cells with Russell bodies. Their general conclusion
is that in certain lymph nodes, modified chiefly through isolation from the lymphatic system, certain lymphocytes are
stimulated to express the partially maintained erythrocytogenic capacity of their immediate hemohistioblast ancestors,
and thus develop into a more or less mature and normal
normoblast or even erythroplastid. Under the suboptimum
condition of lymph-node erythrocytogenesis, it seems reasonable to expect a considerable amount of abortive effort,
resulting in typical plasma cells and cells with Russell bodies.
The conditions in respect of these lymph-node normoblasts
would seem to be the reverse of that which obtains in the case
of the so-called ‘cells of Rieder.’ Lambin (’27) has shown
that these are not a specific cell type, but may represent similar modifications of either monocytes, lymphocytes, myeloblasts, leucoblasts, or reticulo-endothelial monocytoidic cells.
Their common characteristic is a polymorphous or highly
differentiated nucleus, coupled with an immature condition of
the cytoplasm. In other words, Rieder cells are cells in
which nuclear and cytoplasmic differentiations have not run
parallel ; nuclear development has outstripped cytoplasmic
differentiation. Theoretically, there would appear to be no
BLOOD-CELL F O R M A T I O N IN THE H O R N E D TOAD
91
reason why the opposite result should not also obtain; that
is, a condition in which the nucleus has remained relatively
immature. This theoretical condition is apparently realized
in the plasma cells with eosinophilic granules described by
Dubreuil and Favre (’23), and to a less extent in the plasmoidocytes of Maximow, and the erythroblasts of Mottram,
Jordan, and Dawson. Here the nucleus retains largely the
pattern of the lymphocyte at a stage when the cytoplasm has
enlarged its mass and has elaborated either specific granules
or a small amount of hemoglobin. While a few of these latter
cells continue differentiation to a normoblast or later stage,
others enter regressive phases and degenerate into typical
plasma cells and finally into cells with bodies of Russell.
SUMMARY
I n the horned toad the spleen is the chief locus for the
formation of blood cells. There is evidence of a cyclical hemocytopoietic activity. A normal active spleen is characterized
by pulp cords and sinuses, while an exhausted spleen shows
fibrous nodular areas.
The lymphocyte functions as hemoblast and gives rise both
to the red and white blood cells. It is, itself, a derivative of
the reticular cell. Erythrocytes arise from medium-sized
lymphocytes. No indication of endothelial origin could be
seen. Thrombocytes are derived from the small-sized
lymphocytes. Eosinophilic and basophilic granulocytes are
developed from either lymphocytes or reticular cells. Many
of the basophils appear to be abortive and undergo degeneration without becoming mature. They are interpreted as unripe eosinophils. Monocytes also arise from lymphocytes and
possibly from reticular cells. A small, lightly staining,
archoplasmic area is a usual characteristic of these cells.
Plasma cells with vacuolated cytoplasm are fairly numerous
in the spleen. They are interpreted as degenerate hemoblasts (lymphocytes). Of special interest are abnormal types
of differentiating leucocytes, including cells with ‘Russell
bodies. ’ Transition stages in the development of these cells
92
H. E. JORDAN AND C . C. SPEIDEL
strongly suggest that they may come from plasma cells. Cells
with Russell bodies are believed to represent the terminal
stages of the process of plasma-cell degeneration. They
would, therefore, represent hemoblasts (erythroblasts or
granuloblasts) which failed to transform normally into
erythrocytes or granulocytes.
L I T E R A T U R E CITED
AND HTJBER,
E. 1923 Untersuchungen iiber Blutzellen und Zellbildung bei Amphibien und Reptilien. Folia Haematologica, Bd. 29,
s. 1-22.
CHLOPIN,N. G., AND CHLOPIN, A. L. 1925 Die Histogenese der Zellformen in
den Explantaten der blutbildenden Organe des Axolotls. Archiv. fur
exp. Zellfors., Bd. 1, S. 193-250.
DANTSCHAKOFF,
W. 1910 Uber die Entwicklung der embryonalen Blutbildung
bei Reptilien. Anat. Anz., Bd. 37 (Erganzungsheft).
DAWSON,A. B. 1927 Modified lymph nodes from dogs with a known history of
irradiation, including a note on ‘globule ’ leucocyte formation. Anat.
Rec., vol. 36, pp. 1-27.
DOWNEY,H. 1911 The origin a n d structure of the plasma cells of normal
vertebrates, especially of the cold-blooded vertebrates, and the eoshophils of the lung of Amblystoma. Folia Haematologica, Bd. 11,
Teil 1 (Archiv), S. 275-314.
D T J B ~ U I LG.,
, ET FAVRE,
M. 1921 Cellules plasmatiques.
Plasmazellen a
granulations specifiques. Cellules B corps de Russell (cytologie et
formes Bvolutives). Arch. d’Anat. Microscopique, T. 17, pp. 303-360.
JORDAN,
H. E. 1924 The significance of the spleen in the light of embryological, evolutionary and experimental data.
Virginia Medical
Monthly, vol. 51, pp. 537-544.
1926 a The transformation of lymphocytes into erythroblasts in a
lymph node of a rabbit. Anat. Rec., vol. 32, pp. 369-393.
1926 b The erythrocytogenic capacity of mammalian lymph nodes.
Am. Jour. Anat., vol. 38, pp. 255-279.
1927 The reticulo-endothelial system with special reference to the
lymphocyte. Virginia Medical Monthly, vol. 53, pp. 776-782.
JORDAN, H. E., AND FLIPPIN,
J. C. 1913 Haematopoiesis in Chelonia. Folia
Haematologica, Bd. 15, S. 1-24.
JORDAN,
H. E., AND LOOPER, J. B. 1927 The comparative histology of the
lymph nodes of the rabbit. Am. Jour. Anat., vol. 39, pp. 437-461.
JORDAN,
H. E., A N b SPEIDEL,
C. C. 1923 Studies on lymphocytes. I. Effect
of splenectomy, experimental hemorrhage and a hemolytic toxin in
the frog. Am. Jour. Anat., vol. 32, pp. 155-187.
1924 a Studies on lymphocytes. 11. The origin, function, and f a t e
of the lymphocyte in fishes. Jour. Morph., vol. 38, pp. 529-548.
1924 b Studies on lymphocytes. 111. Granulocytopoiesis in the
salamander, with special reference to the monophyletic theory of
blood-cell origin. Am. Jour. Anat., vol. 23, pp. 4 8 5 4 0 5 .
ALDER, A.,
BLOOD-CELL FORMATION I N T H E HORNED TOAD
JORDAN,
H. E.,
93
AND SPEIDEL,
C. C. 1928 Erythrocytophagic capacity of the
hepatic peritoneum in the splenectomized horned toad, Phryposoma
solare. Proc. SOC.Exp. Biol. and Med., vol. 25, pp. 4 9 1 4 9 4 .
KEASBEY,
L. E. 1923 On a new form of leucocyte (Schollenleukozyt, Weill) as
found in the gastric mucosa of the sheep. Folia Haematologica, Bd.
29, 8. 155-171.
LAMBIN,M. P. 1927 Les cellules de Rieder. Ann. SOC.Sci. Bruxelles, T. 47,
pp. 34-37.
MACMILLAN,
RUTH E. 1928 The so-called hemal nodes of white rat, guinea-pig,
and sheep: A study of their occurrence, structure, and significance.
Anat. Rec., vol. 39, pp. 155-176.
MAXIMOW,
A. 1907 Experimentelle Untersuchungen zur postfotalen Histogenese
des myeloiden Gewebes. Beitr. z. path. Anat. u. z. allg. Pathol., l3d.
41, S. 122.
1927 a Morphology of the mesenchymal reactions. Archives of
Path. and Labr. Med., vol. 4, pp. 557-606.
Mollendorff ' 8
1927 b Bindegewebe und blutbildende Gewebe.
Handbuch der mikroscopischen Anatomie des Menschen, Bd. 2, Teil 1.
J. Springer, Berlin.
MOTTRAM,J. C. 1923 Some observations upon the histological changes in
lymphatic glands following exposure to radium. Am. Jour. Med. Sci.,
vol. 165, pp. 4 6 9 4 7 9 .
SCHFLIDDE,H. 1905 Zur HLtologie des Rhinoskleroms, ein Beitrag zur Plasmazellenfrage und zur Genese der hyaline Korperchen. Arch. f. Dermat.,
Bd. 73.
SUGIYAMA,
S. 1926 Origin of thrombocytea and of the different types of blood
cells as seen in the living chick blastoderm. Contr. to Embryol.
no. 97, Carnegie Inst. of Wash., pp. 121-248.
THE A M E R I C A N J O U R N A L O F ANATOMY, VOL.
43,
NO.
1
PLATE 1
EXPLANATION OF FIGURES
1 Longitudinsl section, approximately medial, of the spleen of the horned
toad Phrynosoma solare, showing the lobulation and the structural variation of
different regions. This spIeen is in an intermediate degree of hemopoietic
activity. Along the axis may be seen a number of inactive fibrous nodules, e.g.,
N . Along the periphery the wide sinuses can be recognized alternating with
pulp cords. Below occurs the connective tissue of the hilum, including the
x 50.
splenic vein ( V ) and artery ( A ) . T, trabecula. Photomicrograph.
(Photographs by Mr. Arthur J. Weed.)
(All figures reduced one-third in
reproduction.)
2 Oblique longitudinal section of spleen near hilum, showing the splenic vein
(P) cut longitudinally; the spleen artery ( A ) , transversely. The tissue below,
at right, is a section of the pancreas. This spleen is very active in blood formation. The sinuses are very wide. Many of the sinuses are filled with lymphocytes,
at all stages of maturation into erythrocytes. Some of the sinuses are practically
empty, e.g., above a t left. The large lobule a t the right contains a number of
irregular inactive fibrous nodules, one (below) showing an obliquely cut arteriole
with robust wall. The content of the adjacent portion of the splenic vein is
essentially identical with that of the splenic sinuses. Photomicrograph. x 50.
94
BLOOD-CELL FORMATION IN THE HORNED TOAD
H. E. JORDAN AND C. C. BPEIDEL
95
PLATE 1
PLATE 2
EXPLANATION O F FIGURES
3 Longitudinal section of very active spleen, showing a very large sinus
(above a t left) for the most part empty, and several large irregular inactive
fibrous nodules ( N ) below a t the right. X 50.
4 Oblique section, showing an earlier stage of the blood-forming cycle. Note
the network of pulp cords and sinuses above a t the right. At the left appears a
large, almost empty sinus. X 50.
5 Oblique longitudinal section of a small spleen at a late (relatively inactive)
phase of the blood-producing cycle. Note the very large fibrous nodules ( N ) .
X 50.
6 Transverse section of a spleen in approximately the same condition as
that of figure 4.
7 Portion of a median longitudinal section of spleen a t an early stage of
reactivity. Note the numerous irregular axial nodules of fibrous tissue. The
extranodular parenchyma appears compact and of uniform texture, with little
or no indication of potential cords and sinuses. This parenchyma consists, in
fact, largely of sinuses, well filled with blood cells, especially erythrocytes. The
sinus content includes numerous degenerating lymphocytes. The lymphocytes
of the original pulp cords have largely disappeared. The fibrous nodulan include
generally a central arteriole with its capillary branches, the whole enveloped
by connec&e tissue. The capiIlary portion largely represents previous puIp
cords. Some of the nodules show considerable initial hemocytopoietic reactivity,
a t first along the periphery. X 50.
96
BLOOD-CELL FORMATION I N THE HORNED TOAD
H. E. J O R D A N A N D C. C. SPEIDEL
97
PLATE 2
PLATE 3
EXPLANATION OF FIGURES
8 Portion of reactivated nodule from the spleen of figure 7 at early stage
of hemocytopoietic cycle. The reticulum cells round up and divide by mitosis.
Later proliferation of the young hemblasts (free reticulum cells) is in part
by amitosis.
9 Portion of fibrous nodule a t stage of exhaustion. This nodule also is
from the spleen of figure 7.
98
BLOOD-CELL FORMATION I N THE H O R N E D TOAD
EI. E. JORDAN AND C. C. SPEIDEL
99
PLATE 3
PLATE 4
EXPLANATION OF FIGURES
10 Group of large and small lymphocytes (hemoblasts) in process of separation from the reticular syncytium of a splenic nodule. At the right appear an
erythrocyte, a small lymphocyte, and an eosinophilic granulocyte in a venous
sinus.
These and subsequent cells are all from the spleen. Helly fixation, Giemsa
stain. The drawings were made with a 1/16 Leitz oil-immersion lens, and a
no. 10 compensating ocular. x 2000. Margaret Haase Looper, artist.
11 Reticulum cell in process of separation to become hemoblast.
12 and 13 Successive initial steps in the formation of hemoblasts.
14 Typical round medium-sized lymphocyte. This cell functions as a hemoblast.
15 to 22 Successive stages in the development of the erythrocyte from the
lymphocyte.
23 Binucleated erythroblast. The cells commonly divide by mitosis. The
condition of this cell, may indicate alternative amitosis.
24 Small lymphocyte, ancestor of the thrombocyte.
25 and 26 Successive stages in the development of a thrombocyte.
27 and 28 Monocytes.
29 to 31 Successively older (regressive) stages of basophilic granulocytes.
These are interpreted as abortive eosinophils.
32 Immature eosinophil.
33 Mature eosinophil.
34 Neutrophilic granulocyte.
35 to 38 Successively later stages of plasma cells
39 to 41 Successively older Russell-body cells.
100
BLOOD-CELL F O R M A T I O N IK THE HORNED TOAD
H . K . J O K U A S A N D C . C . SI’EIDEL
101
PLATE 4
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