174 THE SURVIVAL OF THE UNLIKE. [vi. 



nectioii with such reports, the .experimenter can add his 

 own experience, very much will be gained ; and he 

 often has the great advantage of receiving varieties 

 before they are put upon the general market. The 

 greater use he makes of the reports of others, the more 

 valuable does his own variety patch become as a means 

 of study and comparison. 



But there is another feature of this adaptation of 

 varieties to the conditions in which they are desired to 

 be grown, which I wish to bring to your attention. 

 Thus far, I have spoken of such adaptations as are the 

 necessary means of securing good or profitable crops ; 

 but if these changes in the plant, by means of which it 

 becomes fitted to every new condition, are constantly 

 taking place, why is not the modification of the condi- 

 tions of life the readiest means of securing new varie- 

 ties ? This is one of the sources of new plants or 

 varieties, particularly of those which, like the garden 

 vegetables, are propagated by seeds. One variety grad- 

 ually passes or varies into another one, and the modifi- 

 cation is generally so slow that it is wholly unobserved. 

 Many of our garden vegetables have thus grown away 

 from their original types, although they still retain the 

 original name. The Trophy tomato is probably wholly 

 lost to cultivation, the variety now passing under this 

 name being an "improvement" upon the old type in 

 shape and other features. (Essay XXX.) The fact 

 that varieties are constantly changing in the divers 

 localities in which they are grown, renders exact de- 

 scriptions of them impossible. Who can describe the 

 Astrachan apple so that it may be always distinguished 

 from its fellows? Observe, if you will, how the same 

 apple varies, — tending to be solid -fleshed and fine' 



