REPRODUCTIVE SYSTEM. 563 



into the urinogenital canal. Behind the prostate on the 

 dorsal wall of the urinogenital canal lie two Cowper's glands. 



The penis, which projects in front of the anus behind the 

 pubic symphysis, has vascular dorsal walls (corpus spongi- 

 osum), stiff ventral walls (corpora cavernosa), and is invested 

 by a loose sheath of skin — the prepuce. At the side of the 

 penis lie the two perineal glands. 



{b) Female. The ovaries are small oval bodies about 

 three quarters of an inch in length, attached behind the 

 kidneys to the dorsal abdominal wall, exhibiting on their 

 surface several clear projections or Graafian follicles, each 

 of which encloses an ovum. 



The ova when mature burst from the ovaries and are 

 caught by the adjacent anterior openings of the oviducts. 

 The oviducts are modified Miillerian ducts, and are differen- 

 tiated into three regions. The anterior portion or Fallopian 

 tube is narrow, slightly convoluted, with a funnel-shaped ragged 

 or fimbriated mouth lying close to the ovary. The median 

 portion or uterus is the region in which the fertilised ova 

 become attached and are developed. In the rabbit, the 

 uterine regions of the two oviducts are distinct, forming 

 what is called a double uterus. In most cases, the uterine 

 regions of the two oviducts coalesce, forming a bicornuate 

 or a single uterus, according to the completeness of the 

 fusion. In all mammals above Marsupials, the posterior 

 parts of the two oviducts unite in a median tube, the vagina. 



The vagina unites with the neck of the bladder and forms 

 the wide but short urinogenital canal or vestibule which 

 opens at the vulva ventral to the anus. On the ventral 

 wall of the vestibule, lies the clitoris, a small rod-like body — 

 the homologue of the penis. On the dorsal wall lie two 

 small Cowper's glands, and there are also perineal glands 

 as in the male. 



The development of the fertilised ovum is in most respects 

 like that of the hedgehog, which has been already described. 

 In the guinea-pig and some other Rodents, but not in the 

 rabbit, there is a remarkable inversion of the germinal layers. 



There is in the rabbit, as in all Rodents, a provisional 

 yolk-sac placenta. The allantoic placenta is discoidal and 

 deciduate. 



