68 POPULAR ERRORS. 



by tubers alone. Mr. Goodrich produced some 

 good varieties, and greatly improved the wild 

 species, but lie failed to produce any kinds capable 

 of resisting rot, and there are those who think that 

 if he had expended an equal amount of labor in 

 improving the best existing varieties by seed his 

 results would have been greater. 



As to the degeneration of varieties of apples, 

 pears, etc., there are those who doubt that it neces- 

 sarily occurs, and who claim that under suitable 

 conditions varieties of these fruits two hundred or 

 more years old are as valuable as ever. Certainly 

 there are some old sorts of the pear and the apple 

 that retain their character remarkably well. Many 

 others doubtless owe the fact that they are no longer 

 cultivated to the production of newer varieties of 

 greater value. Many sorts also owe their present 

 inferiority in certain localities to changes in the 

 soil or climate since they originated, through con- 

 tinued cultivation of the soil and the clearing up of 

 the forests; or to their having been raised beyond 

 the locality in which their excellence was first 

 discovered. Such varieties are still often grown 

 with success in favored localities. We have little 

 proof, therefore, in plants propagated by grafts 

 and similar means, that varieties necessarily, of 

 themselves, wear out. 



The case of varieties grown from seed is entirely 



