1889.] Embryology. 927 
seen to fill the anterior intestine and extend into the posterior intes- 
tine as a solid rod, usually terminating in a knob. It is very probable 
that the ])rimitive absorption does not cease with the opening of the 
mouth, and that even after the villi are formed it is carried on by the 
now highly vascular fins. The larvae are at no time connected with 
the ovary. 
Next to the feeding, the aeration is of great importance. The 
ovarian structures are well supplied with blood vessels, and the mucus 
contained in the ovary is undoubtedly oxygenated by osmosis, while 
spermatozoa keeps the mucus in circulation. There is, then, nothing 
further to explain as respects the early stages, the conditions being 
similar to those obtaining in pelagic eggs. With the growth of the 
fins they become highly vascular, the blood vessels occupying much 
more space than the remaining structures of the fin membrane. The 
fins also are several times as large as they are in the adult, and the tips 
of the membranes are continued beyond the ends of the rays. The 
fins therefore offer a very large surface in which osmotic action may 
take place. A similar network of capillaries is formed over the 
whole surface of the body. At this time also the ovary has become 
greatly distended, and the inner oviferous sheets have become unfolded. 
The fins can therefore lie directly against the vascular structure of the 
ovary, and osmosis takes place directly l)etween the blood of the 
mother and the blood of the young. 
About twelve young are born at one time. Seven or eight months 
after the young are born they are sexually mature, and contain em- 
bryos._C. H. Eigenmann, San Diego, Cal., Feb 8, i8go. 
On a Brood of Larval Amphiuma. — During the last two or 
three years the writer has been endeavoring to obtain larval Amphiu- 
midae. Recently, Prof. Edmond Souchon. of Tulane University, 
New Orleans, La., has been enabled to obtain some acivanccrl larvae 
for me, in the egg, which he has very generously ])la( cd at niv <]i>i.osal. 
As already described by Hay, the eggs are joined to-cther by a nar- 
row cord formed of the same material as the eu;K < Dvcrin^s. M()>t 
of the embryos had escaped from the eggs when the v readied nic, and, 
owing to the long journey they had made, were dead, though they 
were in a fairly good condition for study after proper treatment 
with Kleinenberg's fluid. 
What has surprised me is the variation in si/e ot these embryos. 
Though all have evidently only just escaped from the egti. and liave 
not had any opportunity to feed, there is a marked (hversity in tlieir 
