HOW THE TROTTIXG HORSE IS BRED. 461 



In former years it was very aptly termed the law of inheritance, 

 but the more general usage is now the law of heredity. In 

 casting about for a definition of this newly coined word, I have 

 not been able to find anything more comprehensive and express- 

 ive than that given by Ribot, in the opening sentence of his work 

 on this subject. He says: 



" Heredity is that biological law by which all beings endowed with life tend 

 to repeat themselves in their descendants; it is for the species what personal 

 identity is for the individual. By it a groundwork remains unchanged amid 

 incessant variation; by it Nature ever copies and imitates herself." 



This has been the law ever since the command went forth, 

 "Let the earth bring forth the living creature after his kind, 

 cattle and creeping thing and beast of the earth after his kind." 

 Hence sprang the varieties, species, genera and orders into which 

 naturalists have sought to classify the animal kingdom. In gen- 

 erations long past our ancestors used such phrases as "Like 

 father, like son," "Trot father, trot mother, trot colt," "Like 

 begets like," etc., meaning just what we mean to-day by the 

 word "heredity." While heredity is a universal law of animal 

 life, it must be remembered that its results cannot be pre-deter- 

 mined by any rule of arithmetic. Every colt has a sire and a 

 dam, four grandparents, eight great-grandparents, and then 

 sixteen, and next thirty-two progenitors. Here we have five 

 generations embracing sixty-two different animals, and the ex- 

 periences of many years have gone to show that if these sixty-two 

 animals are all purely bred in the breed which you are seeking to 

 secure there is a reasonable certainty that your prospective colt 

 will be a good representative of that breed. By this I mean that 

 with this number of generations there is but little danger of your 

 colt following some undesirable type outside of and beyond these 

 five generations. The only way to study this problem intelli- 

 gently and with satisfaction is to tabulate the pedigrees of the 

 two animals you propose to couple and then study each individual 

 of the different generations and see what each one has done in 

 ihe direction you are breeding. If yon are breeding for a Derby 

 winner you want every one of the sixty-two to have proved himself 

 or herself a first-class runner, and you don't want a single drop of 

 outside blood in any of them. If you are breeding for the two- 

 minute trotter, you don't want any blood but the fastest trotting 

 blood. If you are breeding for the two-minute pacer you want 



