THE DEVELOPMENT OF THE POSTCAVAL VEIN IN BIRDS. 
BY 
A. M. MILLER. 
Class-of-77-Fellow-in-Biology, Princeton University. 
WitH 10 Text FIGURES. 
This subject was suggested to me by Professor C. F. W. McClure, under 
whose direction the investigation has been carried on. Professor Mc- 
Clure has shown the greatest kindness and interest during the time of 
my research in his laboratory, for which I am deeply grateful; and I 
- take unusual pleasure in acknowledging my indebtedness to him for the 
most valuable assistance throughout my work. 
The development of the postcaval vein seems to have been much less 
investigated in birds than in the higher and lower forms, Hochstetter’s 
articles being the only ones known to the writer as relating to this sub- 
ject. In reptiles and mammals, on the other hand, the development of 
the posteava has been worked out in several different orders by a number 
of investigators. Hochstetter’s (88, 93) observations on the chick are very 
accurate as recorded in his brief general description; a detailed account, 
however, is lacking. It will be the purpose of the writer in the following 
pages: (1) To corroborate Hochstetter’s general observations on the de- 
velopment of the posteava in the chick; (2) to compare the mode of de- 
velopment in the chick with that in another form, viz.: the English 
sparrow ; (3) to show that a portion of the efferent vessels of the primitive 
kidney (Vv. subcardinales) persists in birds as a part of the postcava in 
the adult, as Lewis (02) has recently shown to be the case in mammals. 
The writer has reconstructed the venous system in a complete series 
of English sparrow (Passer domesticus) embryos, and also in series of 
chicks (Gallus gallus). The veins in the liver region have been recon- 
structed in wax. The burden of the work is based on the sparrow, but 
numerous comparisons have been made with the chick and the modes of 
development in the two forms found to be so very similar, differing in 
only a few unessential points, that figures taken from both are used for 
illustration. The accompanying figures (except Figs. 1 and 8) repre- 
1 Presented to the faculty of Princeton University for the degree of Ph. D. 
20 . : 
