214 THE PRINCIPLES OF BREEDING 



mares, by means of either the gelatine capsule or the impreg- 

 nator — a specially designed syringe — is familiar to most hoi*se 

 breeders. When first advocated, artificial impregnation was 

 opposed by mare owners, but when it is demonstrated that colts 

 so conceived can not be distinguished from colts sired in the 

 natural way, this prejudice gradually disappears. Peter the 

 Great, the leading sire of trotters, got from seventy to eighty 

 foals a year as a result of artificial impregnation being used in 

 his case. 



It is fundamental to the successful practice of artificial im- 

 pregnation to know that the vitality of the male geiTa cell is so 

 susceptible to the infiuence of light and temperature that it must 

 be carefully handled and quickly transferred. " Colts by mail '' 

 is hardly feasible. 



Artificial Insemination. — This method of breeding is re- 

 ported to have been long practiced in crude fashion by the Arab 

 horsemen and by dog men, in a limited way, but it has recently 

 come into more general adoption by horse breeders. The simpler 

 anatomical arrangement of the cervix and the longer heat period 

 of the mare make artificial insemination much more practical in 

 horses than in cattle. 



The objects of resorting to artificial means to inseminate 

 mares are to distribute, yet conserve, the services of a valuable 

 sire, to insure conception in some mares which fail to settle to the 

 ordinary service of the stallion, and to obviate the danger of 

 serving some nervous or irritable mares. 



The technic consists in collecting the seminal fluid from the 

 depressed floor of the vagina of a mare just served by the horse, 

 in the regular way, by means of an uncovered capsule or a 

 syringe, carrying it to the genital tract of other mares ready to be 

 bred and inserting it directly through the cervix into the uterus 

 of these mares. All this must be accomplished without subject- 

 ing the semen to much variation from body temperature, in order 

 not to impair the \atality and motility of the germ cells. It may 

 be advisable to capsule the mare already served by the horse. 



The strictest cleanliness should be obser\^ed throughout the 

 operation and mares showing vaginal discharge or any unhealthy 



