308 THE LIFE OF THE PLANT 



a method which appears paradoxical at first sight, and 

 the logical significance of which is even yet misunder- 

 stood ; or, rather, will never be understood by many of 

 its opponents, whatever explanations may be offered for 

 it. In order to find out how it is that by means of 

 historical development the organic world has reached 

 the degree of perfection we observe in it, Darwin started 

 by inquiring how man reaches the same end, how he 

 improves his artificial breeds of plants and animals — and 

 he came to the conclusion that the main factor in the 

 accomplishment of this end is selection, consisting, as 

 we have already seen,^ in the selection from every 

 generation of only those organisms which correspond 

 most closely to the ends in view. In its simplest and 

 most perfect form selection consists in the extermination 

 of all unfit individuals. For instance, when a gardener 

 wishes to produce or to preserve a certain variety in a 

 plant, he simply exterminates all the plants which do 

 not correspond to his ideal. 



Darwin next raises another question : Does not 

 Nature also advance towards perfection by means of 

 a similar selection ? One has scarcely time to word this 

 question before the opponents of the theory raise their 

 voices in premature triumph and make exclamations 

 such as,-' Can there be anything in common between a 

 process directed by the rational will of man and the 

 action of the blind forces of Nature ? You undertake 

 to explain the origin of organic forms by physical laws, 

 and yet you start by personifying Nature, by endowing 

 it with rational activity, with a capacity for selection.' 

 Unmoved by exclamations of that kind, which are mere 

 words, let us study facts in order to understand the great 

 man's idea. First of all Darwin dwells on cases of what 

 he calls unconscious selection. In, years of famine 

 savages are obliged to kill some of their domestic 

 animals. As a matter of course they preserve the best, 



* See chapter viii. 



