2 54 THE HISTORY OF CREATION. 



I'lants, which obtains at any moment, is simply the 

 necessary result of the momentary predominance which 

 either of these two formative powers (or physiological 

 activities) has acquired over the other. 



If we now return to the consideration of the process of 

 selection or choice, the outlines of which we have already 

 examined, we shall be in a position to see clearly and dis- 

 tinctly that both artificial and natural selection rest solely 

 upon the interaction of these two formative tendencies. If 

 we carefully watch the proceedings of an artificial selector — 

 a farmer or a gardener — we find that only these two con- 

 structive forces are used by him for the production of new 

 forms. The whole art of artificial selection rests solely upon 

 a thoughtful and wise application of the laws of Inheritance 

 and Adaptation, and upon their being applied and regulated 

 in an artistic and systematic manner. Here the will of man 

 constitutes the selecting force. 



The case of natural selection is quite similar, for it also 

 employs merely these two organic constructive forces, these 

 ingrained physiological properties of Adaptation and Here- 

 dity, in order to produce the different species. But the 

 selecting principle or force, which in artificial selection is 

 represented by the conscious will of Tnan acting for a definite 

 purpose, consists in natural selection of the imconscious 

 struggle for existence acting without a definite plan. What 

 we mean by '' struggle for existence " has already been ex- 

 plained in the seventh chapter. It is the recognition of 

 this exceedingly important identity which constitutes one 

 of the gi^eatest of Darwin's merits. But as this relation is 

 very frequently imperfectly or falsely understood, it is 

 necessary to examine it now more closely, and to illustrate 



