60 DARWINISM STATED BY DARWIN HIMSELF. 



most distinct species. Now observe the case of the sev- 

 eral breeds of pigeons : they are descended from a pigeon 

 (including two or three sub-species or geographical races) 

 of a bluish color, with certain bars and other marks ; and, 

 when any breed assumes by simple variation a bluish tint, 

 these bars and other marks invariably reappear ; but with- 

 out any other change of form or character. When the 

 oldest and truest breeds of various colors are crossed, we 

 see a strong tendency for the blue tint and bars and marks 

 to reappear in the mongrels. I have stated that the most 

 probable hypothesis to account for the reappearance of 

 very ancient characters is — that there is a tendency in 

 the young of each successive generation to produce the 

 long-lost character, and that this tendency, from unknown 

 causes, sometimes prevails. And we have just seen that 

 in several species of the horse-genus the stripes are either 

 plainer or appear more commonly in the young than in 

 the old. Call the breeds of pigeons, some of which have 

 bred true for centuries, species ; and how exactly parallel 

 is the case with that of the species of the horse-genus ! 

 For myself, I venture confidently to look back thousands 

 on thousands of generations, and I see an animal striped 

 like a zebra, but perhaps otherwise very differently con- 

 structed, the common parent of our domestic horse 

 (whether or not it be descended from one or more wild 

 stocks), of the ass, the hemionus, quagga, and zebra. 



He who believes that each equine species was inde- 

 pendently created, will, I presume, assert that each spe- 

 cies has been created with a tendency to vary, both under 

 nature and under domestication, in this particular man- 

 ner, so as often to become striped like the other species of 

 the genus ; and that each has been created with a strong 

 tendency, when crossed with species inhabiting distant 

 quarters of the world, to produce hybrids resembling in 



