386 THE SURVIVAL OF THE UNLIKE. [xXIV. 



ties, we shall be forced to conclude that varieties of 

 orchard fruits do not wear because of age. 



2. Do varieties disappear because they are ill -adapted 

 to new environments f Most varieties are more or 

 less local in their adaptations ; that is, they are not 

 suited to cultivation over wide areas which comprise 

 great differences of soils and climates. It must 

 follow, therefore, that those varieties which are most 

 local, and which must require most skill in cultivation, 

 must constantly tend to disappear, because they can- 

 not compete with the more cosmopolitan sorts which, 

 alone, nurserymen find it profitable to propagate. 

 There is a constant selection among the varieties of 

 fruits, which eliminates the least adaptive kinds. This 

 fact is remarkably well illustrated in the relative be- 

 havior in America of the old varieties of European 

 and American origin. In 1817, as I have said, 

 William Coxe made a list of one hundred varieties 

 of apples especially commended for cultivation in 

 North America. Of these, thirty -two are known to 

 be of European origin and fifty -seven of American 

 origin. In 1892, forty of these varieties were sold 

 by American nurserymen, but thirty -three of them 

 belonged to the American group and only seven to 

 the European group. In other words, only 40 per 

 cent of the apples of American origin in Coxe's list 

 have been lost, while 78 per cent of the European 

 group have disappeared. In this instance, therefore, 

 very many of the varieties appear to have passed out 

 of cultivation because they were not well adapted to 

 American conditions. Coxe also listed sixty -five 

 varieties of pears in 1817. Only four of them are 

 now in cultivation, and these are of American origin. 



