258 NEW YORK STATE MUSEUM 



The spermatic duct, as it proceeds along the uterine canal, is in- 

 vested with a yellowish mass, which has been called the prostate 

 gland. In structure it is composed of very closely packed, sim- 

 ple, tubular follicles, which are lined with pyramidal, epithelial 

 cells, containing at their base a nucleolated nucleus. 



At the termination of the uterine canal the male and female 

 organs become entirely separated, forming the vas deferens and 

 the free oviduct (pi. 7, fig. 1, 6, 7, and pi. 14, fig. 1, 18, 19). The 

 vas deferens becomes enlarged, and for some distance assumes 

 a spiral or twisted form; it then contracts, becoming a long, 

 simple tube, somewhat folded on itself, in order to adapt itself 

 to the restricted space which it occupies. It continues to the 

 extremity of the penis, the walls of which are very thick and 

 muscular. The interior passage or duct is, for the greater part 

 of its length, trilobate in section. As it enters the penis it is 

 somewhat enlarged and the orifice is plicated. It is surrounded 

 by thickened lips and folds, which project into the penis. This 

 fold has a plicated membrane (pi. 8, fig. 6), resembling the mem- 

 brane of the fold of the penis previously described, and the outer 

 part is nearly in contact with that fold. 



The urethra is situated between the lining membrane of the 

 penis and the membrane of the muscular fold (pi. 8, fig. 2). 



The retractor muscle of the penis is inserted in the vas deferens 

 at a short distance from the end of the penis (pi. 14, fig. 1, 17). 



Uterine canal. The uterine canal is a large long tube or canal, 

 with plicated or sacculated folds. It is much greater in diameter 

 than the accompanying prostate gland. The walls are mostly 

 composed of polygonal cells, each cell having several nuclei 

 (pi. 7, fig. 1, 8 and pi. 14, fig. 1, 21). It is within this organ that 

 the eggs are completed. 



Oviduct. The oviduct (pi. 7, fig. 1, 7, pi. 14, fig. 1, 20) is about 

 the same size as the twisted part of the vas deferens, and con- 

 tinues from the uterine canal to the vagina, entering that organ 

 near its mouth. 



During coition the penis is everted, passing out of the genital 

 orifice, and entering the vagina of the second animal, coition con- 

 tinuing for several liours. 



