326 DISSECTION OF THE BABBIT 



and receives the urine from the apertures on 

 the pyramids. 



b. The ureters are a pair of slender tubes, running 



back from the kidneys along the dorsal wall of 

 the abdomen, a short distance from the middle 

 line. At the hinder end of the abdomen, they 

 turn inwards and open into the bladder, opposite 

 the anterior border of the pubic symphysis. 



c. The bladder is a thin -walled muscular sac, of 



which the anterior end, in front of the pubic 

 symphysis, can alone be seen at this stage of the 

 dissection. 



2. The reproductive system. 



The testes, in early life, lie against the dorsal 

 wall of the abdomen, close to the kidneys. Before 

 maturity, however, they separate from the dorsal 

 wall, and, slipping down to the ventral wall, pass 

 along the inguinal canals into the scrota! sacs. 



a. The scrotal sacs are a pair of muscular pouch-like 



diverticula of the abdominal wall, lying ventral 

 to the pelvis and close to the median plane. 



Slit up one of the scrotal sacs along its ventral surface to 

 expose the testis lying in it. 



b. The testes. 



The testes are a pair of elongated ovoid bodies, 

 of a pink colour, varying greatly in size at 

 different times, and about an inch and a half in 

 length when fully developed. They are attached to 

 the bottom of the scrotal sacs, but can be readily 

 pulled back into the abdominal cavity. The 

 spermatic arteries and veins, which supply the 

 testes, enter at their anterior ends. 



c. The epididymes are a pair of irregular masses of 



convoluted tubes, lying along the inner edges of 

 the testes. Each epididymis consists of (1) a 

 soft pinkish body, the caput epididymis, in close 



