160 THE SURVIVAL OF THE UNLIKE. [v. 



a very long period of time, had so profoundly modified 

 plants and animals that when the descriptive naturalists 

 appeared last century, they were unable to determine 

 the origin of many of these domestic forms. Even at 

 the present day, with all our study of nature and our 

 inquisitive searching into the uttermost parts of the 

 earth, there are more than a hundred domestic species 

 of which we do not positively know the aboriginal 

 forms. The overwhelming majority of ameliorated 

 forms of plants have appeared in just this way, — as 

 the result of half -conscious or even unconscious and 

 unrecorded efforts. The definite breeding of domestic 

 animals began about the middle of last century with 

 Robert Bakewell, and the breeding of plants may be 

 said to have begun with Van Mons and Knight. Even 

 at the present day, the phenomenal amelioration of the 

 chrysanthemum, rose, potato, and other plants has 

 been, for the most part, undirected. They have devel- 

 oped rapidly because variation has been so rapid and 

 so marked. 



You now ask me why variation has been so marked 

 of recent years. The question is readily answered : It 

 is because the conditions under which plants have been 

 grown are so varied. Better cultivation, greater atten- 

 tion to training and feeding, the growing of plants in 

 many and unlike regions and soils and local conditions, 

 the prodigal exchange of seeds and plants between 

 dealers and buyers, crossing, — all these are the agents 

 which tend to make plants more and more various and 

 unlike. Selection of these variations, by means of 

 which they have been intensified and augmented, has 

 also been more universal and more thorough. The 

 greater the number of persons who grow plants, the 



