CHAPTER XV 



PREPOTENCY 



That all parents are not equally powerful in impressing 

 racial characters is a fact well known to the merest novice in 

 breeding. It is distinctly shown in all regression tables, and 

 the reason for it is clearly seen in the mathematical nature of 

 reproduction, by which individuals are differently endowed, and 

 by which some few are exceptionally rich in the elements out of 

 which racial characters are developed. When to these facts is 

 added the difficulty of selecting animals by outward appearance, 

 on account of the relation of dominant and recessive characters, 

 we need feel no surprise at the relatively small number of 

 highly prepotent individuals and the large number of reversions 

 encountered in actual breeding. 



SECTION I DATA FROM THE TROTTING RECORDS 

 ILLUSTRATING PREPOTENCY 



Seeking material which would illustrate accurately, and with 

 sufficiently large numbers, the differences in the breeding powers 

 of different individuals, the writer made some studies in the 

 records of trotting-bred horses. These studies covered all 

 animals registered and that had made track or breeding records 

 from the opening of the Register and the Yearbook down to 

 and including the year igoi. 1 



In the consideration of this material, and in the comparison 

 of individuals, four facts must be borne in mind : first, some 

 individuals were too young for their full breeding record to be 

 all in ; second, some had enjoyed less opportunity than others, 

 owing to their racing engagements ; third, some stallions had 

 access to better mares, and more of them, than had others ; 



1 It is needless to say that this proved a laborious task, covering many weeks*, 

 with two calculators. 



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