ii DARWIN'S THEORY 79 



simple propositions such as these : All 

 organisms have offspring. These off- 

 spring have an innate and universal 

 tendency to variation from the parent 

 form. These variations are indeter- 

 minate taking place in all directions. 

 Among the offspring thus varying, and 

 between them and other contemporary 

 organisms, there is a perpetual competi- 

 tion and struggle for existence. The 

 variations which happen to be advan- 

 tageous in this struggle from some 

 accidental better fitting into surrounding 

 conditions will have the benefit of that 

 advantage in the struggle. They will con- 

 quer and prevail ; whilst other variations, 

 less advantageous, will be shouldered out 

 will die and disappear. Thus step by 

 step, Darwin imagined, more and more 

 advantageous varieties would be acci- 

 dentally but continually produced, and 

 would be perpetuated by hereditary 



