ITS NEAREST EXISTING RELATIONS 



77 



has been made in improving the pace of the American 

 fast-trotting horse. Between 1818, when records began 

 to be systematically kept, and 1885, the time for a mile 

 heat has been gradually improved from three minutes 

 (the fastest ever accomplished at the former date, and 

 which previously was not thought possible) to two 

 minutes, eight seconds and three quarters, which was 

 attained on July 30 of the last-named year. Although 

 this is at present the highest record, past experience 

 renders it probable that it is not the greatest speed 

 ultimately attainable. As bearing upon an important 

 biological problem, much discussed at the present time, 

 it would be extremely interesting to ascertain, if it were 

 possible to do so, whether this result has been acquired 

 solely by breeding from the fastest animals, and so tak- 

 ing advantage of any, even the slightest, variation which 

 occurs in this direction in order to perpetuate the quality 

 in the race ; or whether the careful training that the 

 parents have had has been capable of producing a direct 

 influence upon the offspring. The first case would be 

 an illustration of the effects of pure selection ( c artificial ' 

 in this instance, but coming under the same category of 

 causes of modification as the c natural selection ' of 

 Darwin and Wallace), the latter, of inheritance of 

 characters acquired during life, the potency of which has 

 been much called in question of late. 



In Australia, as in America, horses imported by the 



