218 
DR. MARTIN BARRY ON THE CORPUSCLES OF THE BLOOD. 
have to offer : and I can scarcely expect the reader to admit the conclusions drawn, 
until he is in possession of the unequivocal evidence, to be derived in no other way 
than by a close examination of the Plates, in connection with the explanation just 
referred to. 
I may here mention, that it is not my object in this memoir, to trace the tissues 
investigated into a perfectly formed state ; but simply to present such of their earliest 
stages, as show them to be derived from objects having the same appearance as cor- 
puscles of the blood. In so doing, I shall have to mention a variety of facts, which, 
though met with incidentally, and recorded without remark, may not be considered 
destitute of physiological interest. 
88. It is important that any one disposed to repeat the following observations, 
should, before entering upon them, carefully notice the colour, — the transparent yellow 
colour, — of the corpuscles of the blood, viewed singly, with a high magnifying power 
(as, for example, the corpuscles in blood obtained by a puncture of the finger) ; so 
that when the same colour is met with elsewhere, he may recognize it. The yellow 
of the magnified corpuscle as thus singly viewed, is obviously that which gives to the 
mass of blood — seen with the naked eye, and by reflected light — its well-known red. 
The reader will bear this in mind, when colour is spoken of in the following memoir. 
89. Some of the observations I am about to communicate, will be found at variance 
with those of other investigators in general anatomy, not excepting even the most 
recent. I have not room, within the limits of a paper, to introduce the opinions of 
the authors referred to. 
90. On former occasions, I have mentioned a certain minute structure, under the 
denomination disc. As the same term will be constantly employed in this memoir, 
it is better, once for all, to define it, as a flat, elliptical or circular body ; usually 
having a concavity in the middle of the flat surface (fig. 141 c5, c>, £.). Frequently, 
however, these minute bodies lose their elliptical or circular form, and assume, as if 
by pressure, a polyhedral shape ; and, in certain states, the concavity becomes an 
orifice. There are also conditions in which a minute projection is presented at this 
part. Numerous examples of discs are to be found in almost every figure which ac- 
companies the paper. 
91. The disc seems in many instances to correspond to the “ cytoblast” of Schlei- 
den ; though his description of the “cytoblast” differs in some material points from 
the definition I have given of the disc'j- : and our experience of the destination of these 
objects is no less different. In the proper place it will be shown that the disc has 
been described by some as a peculiar object, found in two or three kinds of globules. 
92. By division into discs, an expression frequently made use of in this paper, I do 
not mean simple separation. For, from the analogy which seems to exist between 
the mode of propagation of the blood-corpuscle, and that of the cells which are the 
immediate successors of the germinal vesicle in the ovum, there cannot be a doubt 
t See Third Series on Embryology, Philosophical Transactions, 1840, Part II. pars. 385, 425. 
