54 Diseases of the GeJiital Organs 



stituent the spermatozoa, or sperm cells, elaborated by the 

 testicles. Prior to copulation the spermatozoa lie chiefly in 

 the epididymis and vas deferens, being exceedingly concen- 

 trated in these tubules. At the moment of ejaculation, 

 there is thrown into the pelvic urethra the liquid secretions 

 from the vesiculae seminales, prostate and Cowper's glands 

 which serve to dilute greatly the very dense mass of sper- 

 matozoa and facilitate the forcible ejaculation of the semen. 

 Chief amongst these glands in the bull, are the seminal vesi- 

 cles. If these are removed, or are so diseased that their 

 function is impaired or in abeyance, the bull copulates with 

 difficulty apparently owing to the absence of the diluent 

 fluid from these structures. Some think that most or all of 

 the semen is ejaculated directly through the cervical canal 

 into the body of the uterus and that the urethral opening of 

 the male comes in direct contact with or enters the os uteri. 

 Harms, quoting Duranton (Journal de Lyon, 1888) , cites a 

 case of alleged rupture in-the uterine cornu of a cow during 

 copulation, owing to the entrance of the penis of the bull 

 through the cervical canal, but this must have been an error 

 in clinical history. A study of the cervical canal of the cow, 

 as delineated in figures 15, 16, 17, suffices to refute any alle- 

 gation of the entrance of the penis into it. It is an anatomi- 

 cal impossibility. In the mare, with a far more dilatable 

 cervical canal, copulatory injuries from an unusually long 

 penis occur in the vagina — not in the uterus. Male animals, 

 after the amputation of a considerable portion of the penis, 

 are quite as fertile as before, although the stump of the or- 

 gan can not reach the os uteri. Clinically, a large part of the 

 semen is ejected from the vulva of the female immediately 

 after copulation, and quantities of semen are readily ob- 

 tained from the vagina at this time. 



The condition essential to fecundation, so far as the male 

 is concerned, is that physiologically perfect spermatozoa 

 shall gain the cervical canal, traverse the uterus and ovi- 

 ducts, and meet the ovum in the pavilion of the oviduct. Of 

 the countless myriads of sperm cells in one discharge of 

 semen, but one can take part in the fertilization of the ovum. 



The migration of the spermatozoa from the vagina to the 



