Specific Likeness. 101 



unions. Science may have mistaken the case, as 

 science has yet many a mistaken case to rectify. 

 Not so nature. 



in. By the very necessities of the case then, all 

 the individuals of one lineage are endowed with an 

 essential identity, as a family heritage. It shows 

 itself first and radically in the physiological function 

 we speak of, that of mutual fertility for perpetuating 

 their kind. Secondly, it does not fail to reveal 

 itself in form or structure, notwithstanding many 

 variations. For, though individuals and races are 

 quite susceptible of these variations, whether mi- 

 nute, as Mr. Darwin generally supposes, or abrupt, 

 wide and even monstrous, it is noteworthy that 

 such as diverge most from the middle, normal type 

 of a species, are the least stable in maintaining 

 themselves distinct: they tend to fall back and re- 

 sume the more ordinary type. Hence, as we saw in 

 the observations made by Mr. Darwin upon pigeons, 

 the races left to themselves in a wild state did not 

 vary much; they differed only in shades of color. 

 That was the operation of natural selection, or of 

 the native conditions of life; while it was only man's 

 interference and watchful supervision which availed 

 to make races diverge widely, to keep them apart 

 and unmixed; so that, as Mr. Darwin says, the 150 

 races, differentiated by man's artificial selection, 

 would in form and appearance claim to be 

 classified, not only in different species, but in three 

 or four different genera. Some species show less 



