SELECTION B Y MAN. 25 



believing that since they had been domesticated they had 

 all proceeded from a common parent, as any naturalist 

 could in coming to a similar conclusion in regard to the 

 many species of finches, or other groups of birds, in 

 nature. One circumstance has struck me much; namely, 

 that nearly all the breeders of the various domestic 

 animals and the cultivators of plants, with whom I 

 have conversed, or whose treatises I have read, are 

 firmly convinced that the several breeds to which each 

 has attended, are descended from so many aboriginally dis- 

 tinct species. Ask, as I have asked, a celebrated raiser ol 

 Hereford cattle, whether his cattle might not have de- 

 scended from Long-horns, or both from a common parent- 

 stock, and he will laugh 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 Kibston-pippin or Codlin-apple, could 

 ever have proceeded from the seeds of the same tree. In- 

 numerable other examples could be given. The explana- 

 tion, 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 naturalists who, knowing far less of the 

 laws of inheritance than does the breeder, and know- 

 ing no more than he does of the intermediate links in the 

 long lines of descent, yet admit that many of our domestic 

 races are 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? 



PRINCIPLES OF SELECTIOIT A27CIENTLY FOLLOWED, AND 



THEIR EFFECTS. 



Let US now briefly consider the steps by which domestic 

 races have been produced, either from one or from seveial 



