The Origin of Species 



and legs of the several species of the horse-genus 

 and of their hybrids ! How simply is this fact 

 explained if we believe that these species are all 

 descended from a striped progenitor, in the same 

 manner as the several domestic breeds of the 

 pigeon are descended from the blue and barred 

 rock pigeon ! 



On the ordinary view of each species having 

 been independently created, why should specific 

 characters, or those by which the species of the 

 same genus differ from each other, be more 

 variable than generic characters in which they 

 all agree ? Why, for instance, should the colour 

 of a flower be more likely to vary in any one 

 species of genus, if the other species possess dif- 

 ferently coloured flowers, than if all possessed 

 the same coloured flowers ? If species are only 

 well-marked varieties, of which the characters 

 have become in a high degree permanent, we can 

 understand this fact ; for they have already varied 

 since they branched off from a common pro- 

 genitor in certain characters, by which they have 

 come to be specifically different from each other; 

 therefore these same characters would be more 

 likely again to vary than the generic characters 

 which have been inherited without change for 

 an immense period. It is inexplicable on the 

 theory of creation why a part developed in a 

 very unusual manner in one species alone of a 

 genus, and therefore, as we may naturally infer, 

 of great importance to that species, should be 

 eminently liable to variation; but, on our view, 

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