BY JAS. P. HILL. 63 



pleteness I here reproduce the main points in my previous 

 description in explanation of figs. 13, 14 and 15. 



Fig. 13 represents a section through the common median vagina 

 shortly after the point of union of the two canals. It contains 

 here an irregular detritus, but further back contains fragments of 

 what are apparently greatly degenerated broken-up portions of 

 allantoic stalks. Its lumen becomes continuous ventrally with 

 that of the pseudo-vaginal passage, in which there almost imme- 

 diately appear the sections of three allantoic stalks, a larger and 

 more degenerate one measuring -4 mm. by "3 mm. in diameter 

 and two smaller ones, each -2 mm. in diameter (fig. 14, all.s.) As 

 the genital organs reached me with only two young, it may be 

 that the larger stalk has persisted from a previous parturition. 

 These three persistent stalks completely occupy the lumen of the 

 passage (fig. 14). They are closely surrounded by a loose con- 

 nective tissue sheath derived from the surrounding tissue, and 

 strands of the same pass in between and separate the stalks. 

 They are here in a more degenerate condition than in the pre- 

 ceding specimen ; the larger one has undergone marked fibrous 

 degeneration, and into all three connective tissue corpuscles have 

 penetrated. Fig. 15 represents a section through the urogenital 

 strand behind the terminations of the allantoic stalks and shows 

 very clearly the cleft-like nature of the pseudo- vaginal passage, 

 here containing a detritus of red blood corpuscles and cellular 

 elements. 



The urogenital sinus and cloaca were not available for examinii- 



tion. 



iv. /*. obesula, with four 3-7 cm. young. 



The two median vaginal canals, each with a greatly folded 

 lining, continue back and eventually open into each other to form 

 the here e.Ktremely short common median vagina, which extends 

 through only four sections as compared with one hundred and 

 thirtj--one in specimen ii. 



There is now no trace of allantoic stalks in any part of the 

 median vaginal apparatus. The lumen of the median vagina 

 must now be described as ending blindly, since the greatly 



