DARWINISM 



been long domesticated in the East, the gold and silver carps ; 

 and these present great variation, not only of colour but in the 

 form and structure of the fins and other external organs. In 

 like manner, the only domesticated insects, hive bees and silk- 

 worm moths, present numbers of remarkable varieties which 

 have been produced by the selection of chance variations just 

 as in the case of plants and the higher animals. 



Circumstances favourable to Selection by Man. 



It may be supposed, that the systematic selection which 

 has been employed for the purpose of improving the races 

 of animals or plants useful to man is of comparatively recent 

 origin, though some of the different races are known to have 

 been in existence in very early times. But Mr. Darwin has 

 l^ointed out, that unconscious selection must have begun to 

 produce an eTect as soon as plants were cultivated or animals 

 domesticated by man. It would have been very soon observed 

 that animals and plants produced their like, that seed of early 

 wheat produced early wheat, that the offspring of very swift 

 dogs were also swift, and as every one would try to have a 

 good rather than a bad sort this would necessarily lead to the 

 slow but steady improvement of all useful plants and animals 

 subject to man's care. Soon there would arise distinct breeds, 

 owing to the varying uses to Avhich the animals and plants 

 were put. Dogs would be wanted chiefly to hunt one kind 

 of game in one part of the country and another kind else- 

 where ; for one purpose scent would be more important, for 

 another swiftness, for another strength and courage, for yet 

 another watchfulness and intelligence, and this would soon 

 lead to the formation of very distinct races. In the case of 

 vegetables and fruits, different varieties would be found to 

 succeed best in certain soils and climates ; some might be 

 preferred on account of the cpiantity of food they produced, 

 others for their sweetness and tenderness, while others might 

 be more useful on account of their ripening at a particular 

 season, and thus again distinct varieties would be established. 

 An instance of unconscious selection leading to distinct results 

 in modern times is afforded by two flocks of Leicester sheep 

 which both originated from the same stock, and were then bred 

 pure for upwards of fifty years by two gentlemen, Mr. Buckley 



