388 THE SURVIVAL OF THE UNLIKE. [XXIV. 



of any year or decade fail to become popular because 

 they are not adapted to a wide range of conditions, 

 and some of them are almost immediately lost from 

 this reason. This is a forcible illustration that disap- 

 pearance and running out are very different matters. 

 I am becoming more and more convinced that the 

 study of the adaptations of varieties to conditions of 

 soil and climate and other environments, is one of 

 the most important subjects with which the horticul- 

 turist has to do, and that the neglect of it in the past 

 has been a serious hindrance and is a source of 

 much confusion now that the least adaptive varieties 

 are being sifted out. (Consult Essays XVIII. and XX.) 

 3. Are more meritorious varieties supplanting the 

 old f Yes ; not only because they are better adapted 

 to varying environments, as discussed in the last 

 paragraph, but because varieties of greater intrinsic 

 merit are appearing. This, in fact, is the chief in- 

 centive to the origination of new varieties, — this 

 expectation that we shall improve upon present varie- 

 ties. All the changes in our fruit lists mean nothing 

 if they do not indicate that we are progressing. Poor 

 or indifferent varieties are introduced, to be sure, 

 but they soon find their level and disappear ; and 

 thereafter they are classed with those which are said 

 to have run out. If every new country develops 

 varieties specially adapted to itself, then it must fol- 

 low that changes in the original fruit -lists come 

 most rapidly in such countries and that they will 

 afford the greatest list of discarded varieties in any 

 given length of time. Thus American fruit cata- 

 logues appear to contain few very old varieties as 

 compared with European countries, even when allowing 



