102 Dynamic Evolution 



Average Ages of Male Ancestors of 2 : 10 Stallions 



With records Without records 



No. Ages No. Ages 



Grandsires 39 9.92 58 13.35 



G.-G. -sires 38 9.60 147 13.37 



G.-G.-G.-sires ... 18 9.28 315 15.09 



G.-G. -G.-G. -sires. 14 8.25 467 15.98 



109 9-29 987 15.12 



It should not be presumed that the 109 

 horses with records, and the 987 without 

 records represent that many separate and 

 distinct animals. Some animals are repeated 

 many times in these 180 pedigrees, and the 

 repetition of the same animal in many pedi- 

 grees shows what ones breed on. These 

 animals which are repeated in many pedi- 

 grees are brothers and very close relatives 

 of many thousands of other standard regis- 

 tered stallions which do not appear at all. 

 The fact that three-quarters of all horses 

 are born before their sires are 14 years of age 

 compared with the average ages of the sires 

 of 987 animals which did breed on to the 

 2 : 10 trotters, shows that it is the progeny 

 of young sires which have been principally 



