GENERATIVE ORGANS OF SOME CARTILAGINOUS FISHES. 497 
strongly villous; the villi projected two or three lines; the surface, moreover, was 
beautifully vascular, and of a bright vermilion hue. The villi appeared to be 
formed of looped blood-vessels. The yolks belonging to the two embryos in each 
cavity were somewhat different, comparing the external and internal portion ; in 
one instance the outer yolk bag was reduced very small,—the inner had become 
pretty large; in another the case was the reverse,—the outer was the largest. As 
might have been expected, there was a correspondence in the size of the young 
fish: the development of that to which the smaller internal yolk belonged was 
farthest advanced. 
It may be mentioned that one of the uterine cavities, which made a very 
beautiful appearance from its vessels being distended with vermilion blood, was 
put into distilled vinegar; and that, when examined two days after, the vessels 
were found to contain air, as if extricated from the blood during its partial 
solution. 
On the Ist April two small foetal fish, each about two inches in length, 
attached to their ova, were procured from the market. On extraction from the 
parent fish they had been put into water, according to instructions given to the 
Maltese fisherman, and which were observed in other instances. The branchial 
filaments were nearly an inch long, and were numerous. The head was large, 
the eyes very large; distinct marks of spines were apparent anterior to the 
dorsal fins. 
On the 15th April a fish was obtained in which several eggs were found, 
nearly of their full size, attached to the ovaries. In one uterine cavity there was 
a single foetus; in the other, two. No membrane enveloped them; they seemed 
nearly fully formed, and were in immediate contact with the villous surface. 
This was very vascular,—its colour bright red. Two of the young fish were 
opened. The yolk of each egg was in part internal; but the inner yolk was 
small in comparison with the outer, and the sac containing it was even less in size 
than the intestine, which was distended with yolk substance. The stomach was 
empty. The communication between the gut and the inner yolk sac—the vitello- 
intestinal canal—was sufficiently large to allow of the free passage of an ordinary 
surgeon’s probe. The contents of the intestine were of a brighter yellow than 
the yolk in either the inner or outer sac. 
On the Ist October, in a small fish then examined, a single foetus, tolerably 
advanced, destitute of branchial filaments, was found in each uterine cavity. In 
one of the ovaries were minute ova about the size of a millet seed; attached to 
the other were some that were pretty large—about the size of a boy’s playing 
marble: their enveloping membrane was highly vascular. 
On the 22d of the same month a fish was obtained about two feet long. An 
ovum was found in each of its uterine cavities, contained in a delicate transparent 
capsule, which, towards its ends, had a light olive hue and a slight horny appear- 
