346 THE SURVIVAL OP THE UNLIKE. [xX. 



prunes at all seasons and in what we should consider 

 the mdest ways. 



There are certainly instances in which injudi- 

 cious pruning has seriously injured orchards, and 

 possibly there are regions where pruning must be 

 cautiously done, but I do not see that it can be held 

 to account for any of the general failure of apple 

 trees. 



Conclusions. — Apple orchards appear, as a rule, 

 to fail sooner now than they did formerly, but much 

 of the opinion to this effect is exaggerated because 

 of fallacious observation. 



This lessening age is not a degeneracy due to 

 domestication, but it appears to be incidental to 

 methods of cultivation and extensions of apple grow- 

 ing over great areas. 



The chief particular causes appear to be lack of 

 adaptability of varieties to regions and conditions, 

 climates unfitted to the best development of the 

 species, and lack of fertility of soil. 



