THE UROGENITAL SYSTEM 93 



thra. Trace it forward to the urinary bladder, and back 

 to its entrance on the dorsal side of the preputial cavity. 

 At the latter end insert a bristle and push it forward to the 

 urinary bladder. 



The urinary bladder is connected with the ventral wall 

 of the abdomen by the suspensory ligament. As in the 

 male, it temporarily stores urine which it receives through 

 a pair of ureters, one from each kidney. 



Remove the prepuce, its glans, and the clitoris. Pull 

 the cut end of the urethra forward. This exposes the 

 vagina. Separate the vagina from the surrounding tissues 

 and observe that it lies immediately below the rectum. 

 With a pair of scissors slit the vagina throughout its 

 length. The margin of the vaginal orifice is thrown into 

 longitudinal folds, as is also the internal surface of the 

 vagina. The mucous membrane of the vagina is said to 

 be without glands. The two horns of the uterus converge 

 and join the anterior end of the vagina. The latter re- 

 ceives the penis of the male during copulation, and is 

 therefore a temporary receptacle for spermatozoa. Slit 

 each horn of the uterus a short distance in front of 

 the vagina. Insert here a blunt probe into the lumen of 

 each horn until the probe emerges through the external^ 

 orifice (os uterus) into the vagina. There are two ex- 

 ternal orifices, one for each horn, showing that the fusion 

 of the posterior part of the horns is superficial and does 

 not involve the lumen (uterus duplex). The orifices are 

 very easy to locate in an animal well advanced in preg- 

 nancy. They are surrounded by five lobes, one large 

 dorsal lobe, one large ventral, and three smaller ventral 

 lobes. 



Each horn of the uterus is suspended from the dorsal 

 side of the abdominal cavity by the hroad ligament, which 

 may contain considerable fat. This ligament extends an- 



