MALE REPRODUCTIVE SYSTEM 339 



rectum. Behind the symphysis it is continued 

 into the penis. 



f. The penis is an elongated body, projecting from the 



ventral surface of the animal, immediately behind 

 the pelvic symphysis and in front of the anus. 

 It is traversed by the urino-genital canal, through 

 which the urinary and genital products are dis- 

 charged. The posterior or dorsal wall of the 

 penis is very vascular, and forms the corpus 

 spongiosum; while its ventral or anterior sur- 

 face is stiffened by the corpora cavernosa. The 

 free end of the penis is soft, and obliquely trun- 

 cated ; and is invested by a loose sheath of 

 skin, the prepuce. The external aperture of the 

 urethra is a slit-like opening on its posterior 

 surface. 



g. The uterus masculinus is a large median sac, 



slightly bilobed in front, attached to the dorsal 

 surface of the urino-genital canal, into which it 

 opens, and extending forwards along the dorsal 

 surface of the bladder to about the middle of its 

 length. 

 h. The posterior ends of the vasa deferentia are 

 slightly dilated, and run back, side by side, along 

 the dorsal surface of the neck of the bladder, 

 between it and the uterus masculinus. They 

 open separately into the ventral wall of the uterus 

 masculinus, just in front of its communication 

 with the urino-genital canal, and opposite the 

 hinder end of the obturator foramen. 



Slit up the uterus masculinus along one side with scissors. 

 Note the large aperture leading into the urino-genital canal, 

 and, just in front of this, the small paired openings of the 

 vasa deferentia, 



i. The prostate is a series of glandular masses, placed 

 around the dorsal surface and sides of the uterus 

 masculinus and vasa deferentia, and opening by 



z2 



