Sketches from Nature. 315 



and birds closely conform to the type of the 

 parent stock, and that therefore there is little 

 chance of variation. But while this is so, it is 

 equally true that when any "sport" occurs this 

 is tenaciously retained providing it possesses any 

 advantages over its neighbours in the struggle 

 for existence. In this way a new type may be 

 set up, differing so far from the original as in 

 time to rank as a species. 



The great power of variability in animals and 

 plants is probably not yet fully comprehended. 

 We know, however, from Darwin's experiments 

 how many distinct varieties in the case of pigeons 

 have been produced from the wild blue rock, 

 each showing profound modification, not in colour 

 alone, but also in bone structure. Then there 

 are those which show the development of hoods 

 and frills, and others, again, which have within 

 them the homing instinct to an almost incredible 

 degree. All this, of course, has been brought 

 about by man, mostly by selection, and it serves 

 to show how pliable nature is. What has been 

 done to pigeons applies to domestic animals. 

 Given a few years, any monstrosity can be 

 produced, however extravagant ; our shorthorns 

 and blood horses have been produced out of the 

 very sorriest material, and now stand as the 

 idealised types of their kind. And what man 

 does artificially, nature is doing daily, but by slow 

 and sure methods of her own. None but those 



