88 Dynamic Evolution 



and had records slower than standard, two 

 trotters were by Electioneer which had been 

 driven from five to seven miles per day for 

 many years before he got these sons, two 

 other trotters were by Pilot Medium which 

 had been similarly driven, and two were by 

 sires in regard to which we have no infor- 

 mation. 



The detailed examination of the sires of 

 these 58 stallions shows that sires must be 

 dynamically developed by work performed 

 before they can get sons of 2 : 10 quality. 

 If the rate of work is rapid, as in special 

 training and racing, the requisite amount of 

 work can be accomplished in a comparatively 

 short time. But if the work is slower, then 

 more time is required. Also, the fact that the 

 sires which were trained and raced got their 

 sons of 2 : 10 quality principally at times very 

 close to the terminations of their racing 

 careers indicates that a loss of energy due to 

 idleness by the sire can rarely be compen- 

 sated for by any such fortunate combination 

 of qualities existing in the dam. Breeders 



