390 THE SELF-FERTILIZATION OF PLANTS. 



however such increase may be wrought. In Grafting, 

 the condition is supplied, and the good results; and, 

 there, the element of sex, and that of reproduction, 

 are wanting. Each variety possesses some peculiar or 

 other feature which it is necessary, for perfect physio- 

 logical integrity, that the others should have. The 

 fact of the good results being occasioned also by the 

 process of Grafting, is strikingly out of harmony with 

 his idea, of the good being due to some quality, resi- 

 dent in the sexual organs. Crossing is not the cause, 

 but merely one of the occasions, of the good. The 

 ultimate reason of the good effects, is, that the union, 

 or addition, of characters, supplies a deficient integrity, 

 and brings the individual receiving such an accession 

 of features, back to the type, from which it. should 

 never have departed. As frequently remarked, differ- 

 ence, per se, is not the cause; the beneficial effect is 

 wrought, only when there is some positive difference 

 capable of covering, or of supplying, a deficiency. 

 Darwin says (p. 1 74, Vol. ii., Animals and Plants, &c) : 



" The self-impotent Passiflora alata, which recovered 

 its' self-fertility, after having been grafted on a distinct * 

 stock, shows how small a change is sufficient to act 

 powerfully on the reproductive system." 



This case of the self-impotent Passiflora alata be- 

 coming again capable of self-fertilization, shows clearly 

 that no matter how the lost integrity of an individual, 

 is repaired; or how the individual regains the charac- 

 ters, lost by itself, or by its ancestors, the recompense, 

 due a return to the original type, is always paid. 



The above quotation reveals another of his ingenious 



