200 Dynamic Evolution 



sires of Gen. B. These stallions are sons of 

 horses of all ages, but the average of all their 

 sires is about ten years, that being the normal 

 average for the breed. 



These iooo stallions in Gen. A. have about 

 100,000 sons in Gen. B. As the result of tests, 

 principally on mares and geldings of generations 

 A and B, the breeders select 11 00 horses from 

 Gen. B. to become sires of Gen. C. These se- 

 lected horses in Gen. B. are sons of sires averag- 

 ing ten years of age, but they do not come in 

 equal distribution from the 1000 horses selected 

 in Gen. A, that is, they are not one son from each 

 sire and an extra son from each of a part of them. 

 On the contrary, by tests, the breeders decide 

 that certain blood-lines are superior to others, 

 and, as a result, the 1100 selected in Gen. B 

 probably come from no more than 400 of the 

 1000 originally selected in Gen. A. When the 

 breeders selected the horses in Gen. B. they 

 eliminated about 600 horses from their original 

 selection in Gen. A, and when we examine the 

 four hundred which remain we find them to be 

 sons of horses averaging about thirteen years of 

 age. It is evident that the horses eliminated 

 because unable to transmit as much energy as 

 others were principally the sons of young sires. 



The 1 100 selected horses in Gen. B probably 

 have 120,000 sons in Gen. C, out of which the 

 breeders select about 1200 to become sires of 



