ANALOGOUS VARIATIONS, I55 



to reappear in the nK)ngrels. I have stated tliat the 

 most probable hypothesis to account for the reappear- 

 ance 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 ten- 

 dency, 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 com- 

 monly 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 con- 

 fidently to look back thousands on thousands of genera- 

 tions, and I see an animal striped like a zebra, but perhaps 

 otherwise very differently constructed, 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 independ- 

 ently created, will, I presume, assert that each species has 

 been created with a tendency to vary, both under nature 

 and under domestication, in this particular manner, 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 their stripes, 

 not their own parents, but other species of the genus. To 

 admit this view is, as it seems to me, to reject a real for an 

 unreal, or at least for an unknown cause. It makes the 

 works of God a mere mockery and deception; I would 

 almost as soon believe with the old and ignorant cosmo- 

 gonists, that fossil shells had never lived, but had been 

 created in stone so as to mock the shells living on the sea- 

 shore. 



SUMMARY. 



Our ignorance of the laws of variation is profound. 

 Not in one case out of a hundred can we pretend to assign 

 any reason why this or that part has varied. But when- 

 ever we have the means of instituting a comparison, the 

 same laws appear to have acted in producing the lesser dif- 



