X URINOGENITAL ORGANS 523 



A prostate gland {pr), consisting of several lobes, is imbedded in the 

 walls of the uterus masculinus and opens by small ducts on either side 

 of the elevation just referred to ; and a pair of smaller, ovoid Cowper''s 

 glands communicate with the urinogenital canal further back. 



The terminal part of the urethra traverses the copulatory 

 organ or penis (p. 470), the posterior or dorsal wall of which 

 is constituted by a soft vascular portion, the corpus spongi- 

 osum {c. s), while the opposite surface is strengthened by two 

 harder bodies, the corpora cavernosa {c. c), which are closely 

 applied together through the greater portion of their length, 

 but diverge proximally and are attached to the ischia; 



In both sexes a pair of perineal glands (p. gl) open on the perineal 

 spaces (p. 469) at the sides of the penis, and two larger rectal glands 

 {r. gl) lie at the side of the rectum. 



In the female the ovaries (Figs. 125 and 135, ov) are small, 

 ovoid bodies attached by peritoneum to the dorsal wall of 

 the abdomen behind the kidneys, the ovarian follicles or 

 ovisacs (p. 195) forming very small, rounded projections on 

 their outer surface. 



The oviducts, instead of remaining separate along their 

 whole length, are fused proximally to form a wide, median 

 portion, the vagina (Figs. 134 B and 135, vet), opening 

 into the urinogenital canal or vestibule [vb), with 

 which the bladder communicates and which opens ex- 

 ternally at the vulva (Fig. 1 34 B, u. g. a). Into the other or 

 distal end of the vagina, the paired, thick-walled titeri (Fig. 

 135, r. lit, I. ut), or middle portions of the oviducts, open by 

 separate thick-walled apertures. The eggs undergo develop- 

 ment in the uteri, which vary in size according to whether 

 or not they contain embryos, and according to the stage of 

 development of these. Each uterus is continued forwards as 

 a narrow, slightly coiled tube — the anterior section of the 

 oviduct, or Fallopian tube {fl. t) which communicates with 



