14 Diseases of the Genital Organs 



only in the dog, amongst domestic animals, that the prostate 

 gland assumes pathologic importance. 



Cowper's glands are present in solipeds, ruminants, and 

 the cat. They lie on either side of the urethra in the 

 perineal region above the ischial arch. They have little or 

 no known pathologic importance. The glands are absent in 

 the dog. 



3. The Penis 



The penis of domestic animals is normally completely 

 hidden, when at rest, within the sheath, and the glans penis 

 has a second covering, the prepuce. The soliped and dog 

 ordinarily protrude the penis out of both prepuce and 

 sheath during urination. The protrusion of the penis dur- 



Fig. 8— Penis of Calf with Preputial Sac Unopened. 

 S, Sheath ; (7, urethra ; P, prepuce, not yet free from the glans ; G, glans. Be- 

 tween the prepuce and the glans is soft embryonic tissue. J\ fornix ; C, C, corpus 

 cavernosum. 



ing coitus or sexual excitement is brought about by its 

 erection and by the relaxation of the retractor penis muscle. 

 In solipeds and carnivora, the retractor muscle is closely 

 applied throughout its length to the ventral side of the 

 penis, so that the length of the retractor muscle from 

 the tuber ischii to its penial insertion is identical with 

 the length of the penis from the ischial notch to the 

 muscular insertion. In ruminants and swine, the muscle 

 is not closely applied to the ventrum of the penis but 

 passes directly across the postero-inferior mouth of the 

 curvature of that organ without following its course so 

 that the length of the muscle is only about one-half that of 

 the penis from the ischial notch to the muscular insertion. 



