Copulation. Coition 49 



3. Copulation. Coition. 



Natural reproduction in higher animals can only occur as a 

 result of copulation, which, in its turn, is brought about by the 

 irresistible desire of the female, which we term estrum, and the 

 corresponding sexual excitement of the male. Artificially im- 

 pregnation is possible and has been practiced to some extent by 

 breeders, by injecting the seminal fluid of the male into the 

 uterus of the female. 



During the act of copulation the semen from the male is in- 

 jected into the vagina of the female, possibly in part into the 

 uterus. We have no definite data as to where the semen is 

 deposited during copulation. It is thought by man^^ that most 

 or all of it is ejaculated directly through the cervical canal 

 into the body of the uterus, the urethral opening of the male 

 coming in direct contact with, or entering, the os uteri. Harms, 

 quoting Duranton (Journal de Lyon, 1888) cites a case of rupture 

 of one of the cornu of the uterus of a cow during copulation, 

 owing to the entrance of the penis through the cervix. On the 

 other hand, as related below, in case of the mare, with a far more 

 dilatable cervical canal, injuries from too long a penis occur in 

 the vagina and not in the uterus. We have also known of a 

 stallion with a considerable portion of the penis amputated which 

 was quite as fertile after as before the operation, although it 

 would seem that the stump of the organ could not well reach the 

 OS uteri. The es.sential condition to fecundation, so far as the 

 male is concerned, is that physiologically perfect spermatozoa 

 shall gain the cervical canal, traverse the uterus and oviducts 

 and meet the ovum. From among thfe countless myriads of these 

 sperm cells in one discharge of semen, but one of them is essential 

 for the fertilization of an ovum. 



