VARIATION UNDER DOMESTICATION 27 



iaugh you to scorn. I have never met a pigeon, or 

 poultry, or duck, or rabbit fancier, who was not fully 

 convinced that each main breed was descended from a 

 distinct species. Van Mons, in his treatise on pears 

 and apples, shows how utterly he disbelieves that the 

 several sorts, for instance a Ribston-pippin or Codlin- 

 apple, could ever have proceeded from the seeds of the 

 same tree. Innumerable other examples could be 

 given. The explanation, I think, is simple : from long- 

 continued study they are strongly impressed with the 

 differences between the several races ; and though 

 they well know that each race varies slightly, for they 

 win their prizes by selecting such slight differences, yet 

 they ignore all general arguments, and refuse to sum 

 up in their minds slight differences accumulated during 

 many successive generations. May not those natural- 

 ists who, knowing far less of the laws of inheritance 

 than does the breeder, and knowing no more than he 

 does of the intermediate links in the long lines of 

 descent, yet admit that many of our domestic races 

 have descended from the same parents — may they not 

 learn a lesson of caution, when they deride the idea of 

 species in a state of nature being lineal descendants of 

 other species ? 



Selection. — Let us now briefly consider the steps by 

 which domestic races have been produced, either from 

 one or from several allied species. Some little effect 

 may, perhaps, be attributed to the direct action of the 

 external conditions of life, and some little to habit ; but 

 he would be a bold man who would account by such 

 agencies for the differences of a dray and a race horse, 

 a greyhound and bloodhound, a carrier and tumbler 

 pigeon. One of the most remarkable features in our 

 domesticated races is that we see in them adaptation, 

 not indeed to the animal's or plant's own good, but 

 to man's use or fancy. Some variations useful to him 

 have probably arisen suddenly, or by one step ; many 

 botanists, for instance, believe that the fuller's teasel, 

 with its hooks, which cannot be rivalled by any 

 mechanical contrivance, is only a variety of the wild 



