ANIMAL CASTBATION. 17 



of the testicle into the depth of the groin, which con- 

 dition sometimes it is so difficult to overcome in the 

 first stages of the operation. 



The fibrous testicular envelope which we have just 

 seen giving attachment to the cremaster, is a thin 

 membranous bag, elongated like the neck of a bottle 

 around the spermatic cord, which it envelopes, and 

 dilated below, in order to enclose the testicle. Lined 

 internally by the serous coat, to which it intimately 

 adheres, this last membrane is a duplicature of the 

 peritoneum, drawn downwards by the testicle when 

 it descends from the abdominal cavity into the in- 

 guinal canal. This serous envelope has, therefore, 

 two coats, one lying on the inside of the fibrous tunic, 

 and called the parietal, and that which covers the 

 cord and the testicle and is known as the visceral. 

 These two layers approximate towards the posterior 

 border of the cord, and, as they unite, form a sort of 

 fold, band, or septum which divides into two parts the 

 posterior portion of the vaginal cavity, and becomes 

 a means of solid adhesion between the tail of the epi- 

 didymis and the bottom of the sac. 



The testicles, thus covered by the visceral layer of 

 the serous coat, are suspended at the end of the sperm- 

 atic cord, and surmounted upon their superior border 

 by the epididymis, the first part of the deferent canal, 

 which is folded upon itself, while at its posterior ex- 

 tremitythe "tail," so called it continues in a 

 straight course, and conveys the product of the secre- 

 tion of the testicles into the vesiculae seminales, 

 lodged in the pelvic cavity. 



