The Male Genitalia 9 



pendicular to the long axis, shifts its course and leaves the 

 head end of the testicle in a direct line parallel to the long 

 axis of the gland. This causes the vas deferens to turn ab- 

 ruptly at E and follow the mesorchium on its median sur- 

 face along the testicle until at the cephalic end of the latter, 

 it joins the artery to contribute to the spermatic cord. In 

 the bull the gubernaculum is anchored in the median wall of 

 the scrotum with the result that both the epididymis and vas 

 deferens are normally applied against the postero-median 

 side of the testicle, as shown in Figs. 2-4, the epididymis 

 behind, and the vas deferens in front of the mesorchium. 

 The head of the epididymis of the bull begins superiorly 

 upon the lateral surface of the cephalic end of the testicle, 

 passes across the posterior surface upward, medianward, 

 and then downward, in the form of an arc. It is flattened 

 against the surface of the testicle and is not materially en- 

 larged to form a "globus major" as in the horse. The tail 

 of the epididymis, or globus minor, on the other hand, is 

 large and prominent. It projects definitely beyond the cau- 

 dal end of the testicle and lies chiefly on the postero-median 

 surface where it is readily palpable and visible through the 

 scrotum. It is the dominant seat of infection in the epi- 

 didymis, with or without abscessation, and as such merits 

 special attention. 



The descent of the testicle of the horse is at first funda- 

 mentally the same as that of the bull but upon reaching the 

 scrotum, the head end tilts forward and finally comes to rest 

 with its long axis parallel to the spinal axis. The epi- 

 didymis consequently lies upon the dorsal surface of the 

 testicle, lateral to the mesorchium, and the vas deferens, in- 

 stead of turning forward along the median side of the 

 mesorchium, is free from the gland and upon leaving the 

 tail of the epididymis, passes directly upward and forward 

 to join the artery near the external abdominal ring. This 

 results in a very marked difference in relation and subjects 

 the testicle of the horse to the possibility of torsion. 



After the vas deferens has joined the spermatic artery, its 

 behavior is essentially alike in all species. It accompanies 



