228 
DR. MARTIN BARRY ON THE CORPUSCLES OF THE BLOOD. 
quently Schwann, succeeded in tracing into the cells of the epidermis. The latter 
supposes that a cell-formation takes place immediately on the surface of the cutis T- 
But here I cannot help referring to the process of division we have seen reproducing 
the epithelium-tables of the Tadpole ; a process which it seems probable, from other 
of my observations, is universal, including, therefore, even the epidermis. 
The Elements of Blood-vessels compared with Corpuscles of the Blood. 
130. Capillaries in the course of formation out of corpuscles having the same ap- 
pearance as corpuscles of the blood, are represented in fig. 107. These corpuscles, 
still red (a), apply themselves together so as to form an object resembling a neck- 
lace composed of elliptical beads; and having coalesced, and become pale (/3), and 
the membranous partitions (at the extremities of the beads) having disappeared, they 
constitute a tube. The membrane of this tube is formed in the same manner as, ac- 
cording to my observations, the membrane of the ovisac, the chorion, and other 
membranes ; — namely, by the coalescence of discs, as at « in the upper part of the 
above figure. At certain parts, the corpuscles apply themselves in such a manner 
as to form a branched vessel. An example of this is to be found in the figure ; 
which also shows the corpuscles, coalescing in this instance for the formation of ca- 
pillaries, to have been of very minute size. They had the same appearance as young 
corpuscles of the blood. At c> is a round space. This space was colourless, and 
brilliantly pellucid. And I am by no means sure that it was not an orifice left in the 
membrane of the tube (pars. 152, 162, 178.). 
131 . If the vessels have their origin in corpuscles of the blood, it is scarcely needful 
to inquire from what source they derive the materials for their thickening also, and 
for the formation of the several coats of which they become composed. It may be 
mentioned, that some of the pale discs in fig. 142. — -evidently derived from corpuscles 
of the blood — seemed, by coalescence, to be entering into the formation of the mem- 
brane of the vessel. But here also, as appears to be the case in every other tissue, 
the original corpuscles (fig. 1 07 -) no doubt contain within themselves the means of 
perpetuation. 
132. While the investigations forming the subject of this memoir were in progress, 
I received a letter from Dr. W. B. Carpenter, of which the following is an extract. 
It requires no comment, except the expression of my concurrence, as furnished by the 
foregoing observations : — “ Having been just lecturing on the blood and the process 
by which it becomes organized, I think it well to mention to you some views which 
have occurred to my mind in reference to your observations on the conversion of 
blood-corpuscles into tissue^. When lymph is thrown out upon an inflamed mem- 
brane, and is in process of becoming organized, it has been long known that the 
t Schwann, l. c., p. 86. 
I Dr. Carpenter here refers to my first paper on the Corpuscles of the Blood, Philosophical Transactions, 
1840, Part II. 
