THE ABDOMEN AND ITS CONTENTS II7 



exterior nearly to the bladder. This will expose a small 

 opening, the vaginal orifice, situated in the mid-dorsal wall of 

 the urinogenital sinus and about one cm. caudad to the bladder. 

 Probe through this opening with the seeker or grooved director. 



MALE RABBIT 



The method of dissecting the pelvic viscera of the male is 

 essentially the same as that for dissecting the female rabbit. 

 It is best to delay excising the pelvic viscera until a brief 

 examination of the external genitalia has been made (see Penis, 

 Method) . 



The scrotum should be examined externally and by inserting 

 the grooved director from the abdominal cavity through the 

 inguinal canal into it; then slit the inguinal canal and the 

 scrotum open from the abdominal cavity to its caudal end. 

 Notice that the scrotum is essentially a continuation of the 

 abdominal cavity and that its muscular wall (cremaster muscle) 

 is covered by a continuation of the peritoneum. This wide, 

 persistent inguinal canal makes it possible for the rabbit to 

 withdraw the testes into the abdominal cavity at will. The 

 caudal end of the testis is attached to the cremaster muscle. 

 There are two systems of blood supply to the testis; the genital 

 artery (50) and vein, which make contact with the cranial 

 end, and branches of the iliac vessels, with the caudal end. 

 The branches from the iliac vessels parallel the vas deferens 

 (spermatic duct) to the extreme caudal end of the testis. 

 Intra-, and inter-anastomoses are common between the arteries 

 of the two systems as well as between the veins. 



The penis is usually partly everted in embalmed rabbits. 

 Method: Make an incision through the skin to the pubic sym- 

 physis and continue this incision caudad passing between the 

 scrotal sacs and on either side of the penis and anus to the dorsal 

 side of the anus. The scrotal sacs may be freed from the 

 limbs at this time. Cut through the symphysis and evert 

 the anus and penis into the abdominal cavity, as directed for 

 the female, p. 116. Note the muscular attachment and blood 



