28 DARWINIANA. 



" I have discussed the probable origin of domestic pigeons 

 ■at some, yet quite insufficient,- length ; because when I first T^ept 

 pigeons and watched the several kinds, knowing well how true 

 they bred, I felt fully as much difficulty in believing that they 

 could ever have descended from a common parent as any natu- 

 ralist could in coming to a similar conclusion in regard to many 

 species of finches, or other large groups of birds, in Nature. 

 One circumstance has struck me much ; namely, that all the 

 breeders of the various domestic animals and the cultivators of 

 j)lants, with whom I have ever 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 of Here- 

 ford cattle, whether his cattle might not have descended from 

 long-horns, 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 dis- 

 tinct species. Yan Mons, in his treatise on pears and apples, 

 shows how utterly he disbelieves that the several sorts, for in- 

 stance a Eibston-pippin or Codlin-apple, could ever have pro- 

 ceeded 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 

 difierences 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 diff*er- 

 ences accumulated during many successive generations. May 

 not those naturalists who, knowing far less of the laws of in- 

 heritance 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 ? " 



The actual causes of variation are unknown. Mr. 

 Darwin favors the opinion of tlie late Mr. Kniglit, the 



