106 



CHAPTER VIIT. 



THE REPRODUCTIVE ORGANS AND THE CLOACA OF 



THE FROG. 



A. The Male Frog. 



1. The Reproductive Organs. (Fig. 3, p. 18.) 



Pin the frog on its hack under water : open the body cavity from 

 the ventral surface : turn aside the alimentary canal and liver. 



i. The testes are a pair of yellow ovoid bodies about 

 half an inch long, lying on the ventral surface of 

 the kidneys. Within the testes are developed the 

 essential male elements or spermatozoa. 



ii. The vasa efPerentia are a number — usually 10 to 

 12 — of slender ducts, connecting the testis of 

 each side with the inner or median border of the 

 corresponding kidney : they serve to convey the 

 spermatozoa from the testis into the tubules of 

 the kidney, whence they escape by the ureter, 

 which acts as vas deferens. 



iii. The vas deferens or ureter runs along the outer 

 side of the posterior part of the kidney, and then 

 backwards to the cloaca. 



iv. The vesicula seminalis is a large pouch-like dilata- 

 tion on the outer side of the vas deferens, just 

 behind the kidney and before reaching the cloaca. 



2. The Cloaca. (Cf. Fig. 3, p. 18). 



Lay the frofi on its back: tvith a stout scalpel split the pelvic 

 symphysis in the median plane : gently separate the tivo halves, and 

 pin them out right and left, so as to expose the cloaca from, the 

 ventral surface. 



