Speed of Racehorses 



of a snipe. In the case of racehorses, which 

 have been selected so carefully through a long 

 period of time, we seem to have reached the 

 limit of speed which can be attained by the mul- 

 tiplication of insignificant variations. We do not 

 wish to dogmatise, but we believe that of late 

 years there has not been any material increase 

 in the speed of our racehorses. 



Mr S. Sidney says, on page 174 of Cassell's 

 Book of the Horse : u As far as form went {pace 

 Admiral Rous), the British racehorse had reached 

 perfection in 1770, when ' Eclipse ' was six years 

 old." He quotes the measurements of the 

 skeleton of " Eclipse " in the Museum of the 

 Royal College of Surgeons as evidence of this. 

 All the efforts of breeders, then, have failed 

 appreciably to improve the form of the British 

 racehorse in the course of over a century and 

 a quarter. 



De Vries has made some important experi- 

 ments with a view to determining whether or 

 not there is a limit to the amount of change 

 which can be induced by the selection of 

 fluctuating or continuous variations as opposed 

 to mutations. " I accidentally found," he writes, 

 on page 345 of Species and Varieties : their 

 Origin by Mutation, " two individuals of the 

 * five-leaved ' race (of clover) ; by transplanting 

 them into my garden I have isolated them and 

 kept them free from cross-fertilisation with the 



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