DR. MARTIN BARRY ON THE CORPUSCLES OF THE BLOOD. 
203 
substance is required to produce the separation in question; this separation being- 
natural, apparently common to nuclei in general, and forming part of the process by 
which cells are reproduced. We found that young cells originate through division 
of the nucleus of the parent cell, instead of arising as a sort of “ product of crys- 
tallization, in the fluid cytoblastema” of the parent cell, as since supposed by 
Reichert'!'. The so-called nucleolus had been described as a distinct object, exist- 
ing before the nucleus. But, we saw the nucleolus to be merely one of a series of 
appearances arising in succession, the one within the other, at a certain part of the 
periphery of the nucleus ; and continuing to arise even after the formation of the cell. 
55. My later investigations, I have now the satisfaction of stating, confirm the 
opinions just referred to, as well as others which I formerly expressed, but which are 
not recapitulated here ; and the object of the present paper is to show, that they 
admit of being extended to the corpuscles of the bloody. 
56. The observations recorded in this memoir are based on an examination of the 
blood in all classes of vertebrated animals, in the embryo of Mammalia as well as 
that of Birds, and in some of the Invertebrata. 
5 7. In certain states of the corpuscle of the blood its nucleus is single, like the 
central portion of the germinal spot in the germinal vesicle of the ovum. Such is 
the case at a in Plate XVIII. fig. 51. and at ?? in fig. 54. from Fishes, at « in figs. 49 
and 50. from two of the Reptilia, at (3 in figs. 43 and 45. from the Bird, and in fig. 32. 
from the Mammal. In all the blood-corpuscles now referred to — which it will be 
seen are those of the four classes of vertebrated animals, including the two divisions 
of both Reptiles and Fishes, — the nucleus has a cavity or a depression ; at the margin 
of which there occurs a high refraction of light. The appearance thus produced, 
seems to represent one of the states of the “ nucleolus” of authors, in other cells. 
58. The centre of the germinal spot undoubtedly communicates at a certain period 
with the exterior of the germinal vesicle ; for strong presumptive evidence was 
brought forward, showing the introduction of some substance into the centre of this 
spot from the exterior of its vesicle. And, besides, I mentioned that in a certain 
f Das Entwickelungsleben im Wirbelthier-reich, 1840, p. 2. 
i They probably admit of being extended much farther. I cannot, indeed, but recognize in a paper by Pro- 
fessor V alentin, not merely dissent (in some instances at least) from the view above referred to, — that the 
nucleus is cast off as “ useless,’’ — but also facts which go to corroborate some of my own observations ; how- 
ever little the conclusions at which I arrived, resemble those of the author now mentioned. See Muller’s 
Archiv, 1840, Heft II. pp. 229, 230, and 235. The recent work of Reichert also, before referred to, contains 
observations respecting which I would make the same remark. This author, however, adopts the mistaken 
Hew, that the nucleus of the cell is absorbed. For, considering the germinal vesicle as a nucleus, he therefore 
supposes it to disappear ( l . c., pp. 102, 103). The “ finely granular” and “ globular precipitate” of Reichert, 
appearing around the nucleus, evidently arose from decomposition of the free portion of the nucleus (See my 
Third Series, l. c., par. 391): to which cause seems referable the reduction he observed in the size of this 
object ( l . c., p. 91). 
2 E 
MDCCCXLI. 
