The Sheatli and Prepiicc 



17 



slowly yields and the preputial sac opens, after which the 

 penis may be protruded. If the young animal is castrated 

 early, the formation of the prepuce is held in abeyance at 

 varying stages. The animal must then urinate within the 

 sheath throughout life and is subject to special diseases not 

 observed in entire males. In the young lamb, the urethral 

 orifice at the tip of the vermiform appendix of the penis 

 opens into the fundus of the sheath, the tip of the vermiform 

 appendix accordingly indicating the line of demarcation be- 

 tween the sheath and the eventual preputial sac. 



Fig. 10 — Sheath, Prepuce and Retracted Penis of Bull. 

 F. Fornix ; G, glans ; P, prepuce ; S, sheath. 



The epithelial coverings of the glans penis and the pre- 

 puce of solipeds are corneous and highly protective. They 

 produce a moist sebum in the sinus about the urethral open- 

 ing, but over the rest of its surface the sebum is normally 

 dry and forms gross masses of crusts which are readily 

 detached. In ruminants, swine, and carnivora, on the con- 

 trary, the preputial sac and glans penis are covered by a 

 very delicate mucous membrane which normally secretes 

 sufficient mucus to keep the parts constantly moist. The 

 prepuce of ruminants and of swine is accordingly more 

 vulnerable to abrasions and infections than that of solipeds, 

 and affects quite profoundly the type of lesions observed in 

 the two classes. The preputial secretions are not as a rule 

 markedly odoriferous. 



The sheath of all domestic animals secretes a smegma 

 having a specific odor. The boar has two culs-de-sac in the 

 superior wall of the sheath which may contain as much as a 



