318 THE SELF-PEETILIZATION OP PLANTS. 



to save varieties from extinction, the following asser- 

 tion of Darwin may be quoted : 



" Whether," says he . (p. 397, Vol. i, Animals and 

 Plants, &c), " the incessant supply of new varieties, is 

 partly due to * * occasional and accidental crosses, 

 and their fleeting existence' to changes of fashion ; or, 

 again whether the varieties which arise after a long 

 course of continued self-fertilization, are weakly and 

 soon perish, I cannot even conjecture." 



The doubt, in his mind, as to their becoming 

 weakly, and perishing, arises probably from the fact, of 

 his having observed several varieties which, — being 

 proportionately developed, — contravene his incomplete 

 induction. 



The loss, or reduction, of characters, entails loss of 

 fertility. This fertility may be regained by the restora- 

 tion of such lost or reduced characters. It matters 

 not, by what process is effected the addition of char- 

 acters to a defective variety, to make up the comple- 

 ment necessary to induce fertility, or increase of fer- 

 tility. If the result be attained by direct reversion (i. e., 

 by what is called improvement), the fertility ensues: 

 If by crossing, the same gain follows. Even when 

 a measurable return to perfect type, is secured by that 

 addition of characters, which is effected by splicing 

 two varieties together, in Grafting, the good equally 

 results. 



As Darwin remarks (p. 1 2, Origin of Species) : 



" It is really surprising, to note the endless points in 

 structure, and constitution, in which the varieties and 

 sub-varieties," (" of some of our cultivated plants 

 as the " varieties of the " hyacinth, potato, even the 



