30 DARWimANA. 



The common proposition is, that sjyecies Teproduce 

 their like I this is a sort of general inference,, only a 

 degree closer to fact than the statement that genera 

 reproduce their like. The true proposition, the fact in- 

 capable of further analysis, is, that individuals repro- 

 duce their like — that characteristics are inheritable. 

 So varieties, or deviations, once originated, are perpetu- 

 able, like species. Not so likely to be perpetuated, at 

 the outset; for the new form tends to resemble a 

 grandparent and a long line of sunilar ancestors, as 

 well as to resemble its immediate progenitors. Two 

 forces which coincide in the ordinary case, where the 

 offspring resembles its parent, act in different direc- 

 tions when it does not and it is uncertain which will 

 prevail. If the remoter but very potent ancestral in- 

 fluence predominates, the variation disappears with 

 the life of the individual. If that of the immediate 

 j)arent — ^feebler no doubt, but closer — the variety sur- 

 vives in the offspring ; whose progeny now has a re- 

 doubled tendency to produce its own like ; whose pro- 

 geny again is almost sure to produce its like, since it 

 is much the same whether it takes after its mother or 

 its grandmother. . 



In this way races arise, which under favorable con- 

 ditions may be as hereditary as species. In following 

 these indications, watching opportunities, and breed- 

 ing only from those, individuals which vaiy most in a 

 desirable direction, man leads the course of variation 

 as he leads a streamlet — apparently at will, but never 

 against the force of gravitation — to a long distance 

 from its source, and makes it more subservient to his 

 use or fancy. He unconsciously strengthens those 



