THE PROBLEM OF DOMESTICATION 251 



tions of civilization. With rare exceptions the individuals of 

 each species are so numerous that, like the insects, they 

 escape by their numbers the risk of the extinction of their 

 kinds. Moreover, the ease with which nearly all the kinds 

 can be brought under cultivation, and the fact that they 

 present no self-will to be dominated, makes the task of deal- 

 ing with them, in a protective way, infinitely easier than in 

 the case of animals. So far as we know, there has not been 

 an instance in which a continental species of plant has been 

 exterminated by man, while there are a number of the 

 larger animals which have been swept away apparently by 

 human agency, and there are many more which are on the 

 verge of extinction. Therefore, so far as the plant world is 

 concerned, we may for the present at least trust the spe- 

 cies to their own powers to maintain them against the rude 

 assaults of civilization. If here and there one is overrun by the 

 wheels of our economic engines, something of value to the 

 student is lost, but the loss does not include the element 

 of mind which is hereafter to be the subject of so much 

 study. 



The foregoing considerations make it evident that the 

 problem of domestication shades into the question as to the 

 preservation of the life which is now on the earth, and this 

 with a view to the advantage which the arts, the sciences, or 

 general culture may obtain from the preservation of the use- 

 ful, the instructive, and the beautiful things in the realm of 

 nature from the swift destruction which our rude subjugation 

 of the earth threatens to inflict. To deal with this problem 

 in an adequate manner we must ask ourselves what limits are 

 to be set to the displacement of the ancient order which is 

 now going on. We see that wherever civilization enters, and 



