EENAL AND"REPRODUCTIVE SYSTEMS. 



"263 



while the mesonephros and its ducts form the functional 

 kidney and ureters of the adult. 



In the male the Miillerian ducts are abortive and func- 

 tionless ; the anterior mesonephric tubules become connected 

 with the vasa efierentia of the testis, conveying the sperma- 

 tozoa to the mesonephric or Wolffian duct, which acts as vas 

 deferens. The posterior part of the kidney and its ducts, as 

 in the female, become the functional kidney and ureters. The 

 tubules of the kidney have persistent peritoneal funnels 

 opening into the body-cavity. 



TABLE SHOWING THE EMBRYONIC AND ADULT CONDITIONS OF THE 

 KIDNEYS AND THEIR DUCTS. 



A. The Female. 



1. The ovary, which is single, is an elongated soft lobu- 

 lated mass, varying a good deal in size, but usually 

 about two or three inches long in specimens of the 

 size described. It lies in the abdominal cavity a 

 little to the right of the median plane, and is 

 attached to the dorsal wall by a narrow fold of 

 peritoneum, which is very easily torn. The ova 

 form conspicuous rounded projections on the sur- 

 face of the ovary, and when fully formed are half 

 an inch or more in diameter. 



2. The oviducts, which are formed from the Miillerian 

 ducts of the embryo, are a pair of tubes running 



