MALE OKGANS OF RODEXTS. 



653 



508 



unprovided with the horny armature which gives it so remarkable 

 a character in the Cavies. 



In the Beaver (Castor canadensis) I have usually found the 

 testes, fig, 508, r, s, though small in proportion to the bulk of 

 the animal, lodged in subcutaneous depressions between the 

 castor-bags ; but with the usual wide opening of the ' tunica 

 vaginalis,' permitting easy re- 

 turn of the inland into the 



o 



abdomen. The tortuous dis- 

 position of the vasa deferentia 

 would favour such periodical 

 movements of the testes : the 

 terminal portion of the ducts, 

 fig. 508, a, is dilated, or en- 

 larged by glandular thickening 

 of the walls, the inner surface 

 of which is multiplicate. The 

 vesicular glands are (for Ro- 

 dents) moderate sized convo- 

 luted bags, fig. 508, o, p : the 

 duct, fig. 509, d, sometimes 

 communicates with, sometimes 

 terminates distinctly from, the 

 contiguous vas deferens, ib. a. 

 The prostatic glands, ib. c, c, 

 are a cluster of shorter pyri- 

 form sacs, the Ions; slender 



3 O 



ducts of which intercommuni- 

 cate before terminating in the urethra. The protometra, ib. b, b, 

 soon divides, after its communication with the urethra, into two 

 long ( cornua,' which lie on the peritoneal fold behind the neck of 

 the bladder, mesiad of the vasa deferentia, the course of *vhich 

 they follow till they become too attenuated for distinction. The 

 Cowperian glands, fig. 508, ?, ?i, are of a compact oval form, 

 situated between the ' erectores' and ' acceleratores ' muscles ; and 

 opening into the bulb of the urethra. The maximised preputial 

 glands, ib. e, f } and ano-preputial glands, y, k, It, i, have already 

 been described. 



In the Water-vole (Armcola amphibia) the epididymis, fig. 510, 



f, y. is connected by longer ( vasa efferentia ' than usual with the 



testes, ib. c, d. The vesicular glands, ib. k, /, relatively larger 



than in Castor, are bent upon themselves, and subdivided along 



one border: each prostate consists of three lobes, ib. m r, or 



Male organs, Beaver, cxxi". 



