138 



BIOLOGY OF THE LABORATORY MOUSE 



ing which has been frequently reproduced, illustrated the male urogenital 

 system of the mouse and labelled this gland prostate I. The other two 

 prostates are dorsally and ventrally located and will be designated in the 

 text as dorsal and ventral prostates. Rauther referred to these as prostate 

 II and III respectively. Occasionally the two lobes of the dorsal prostate 

 are connected by a very small median lobe, but more often this lobe is 



— ^Epithelium 

 Lamina propria 



Circular mus- 

 cle layer 



Longitudinal 

 muscle layer 



Fig. 66. — Ductus deferens. Fixed in Bouin's fluid. (X66i2-) 



absent. Around the base of the ductus deferens is a small group of glands 

 whose ducts open into the ampulla. These are the ampullary glands (Fig. 



63)- 



Figure 67 is a composite drawing of three adjacent sagittal sections of 

 the urethra, slightly lateral to the midline, showing the entrance of some of 

 the structures joining it. A short description of the more lateral sections 

 is needed. The lateral wall of the cephalic end of the urethra is surrounded 

 by the coagulating gland and the ventral and dorsal prostates. The dorsal 

 prostate has many ducts, some of which are lateral to all the other ducts 

 entering the urethra. Each coagulating gland has two ducts; they enter 

 the dorsal wall of the neck of the bladder. The ventral prostate has several 

 ducts which have a curved course caudad to the neck of the bladder, and 

 enter the ventral wall of the urethra. The ductus deferens opens into a 

 vestibule, the ampulla, which narrows down considerably before entering 

 the urethra. Each vesicular gland has a rather wide duct and enters in 



