26 



useful to the surviving and modified creature. Consequently, 

 those in which the most useful modifications are produced, 

 that is, those which are best adapted to the environment in 

 which they live, survive and transmit their beneficial modifica- 

 tions by procreating their kind. What Darwin means, then, by 

 Natural Selection is that Nature forms species from that selec- 

 tive breeding which is the necessary consequence of the exter- 

 mination of rivals and survival of the fittest in the struggle 

 for existence. The laws governing the process of Natural 

 Selection are, according to Darwin, as follows: " * * * these 

 laws, taken in the largest sense, being Growth with Repro- 

 duction; Variability, from the indirect and direct action 

 of the external conditions of life, and from use and disuse; a 

 Ratio of Increase so high as to lead to a Struggle for Life, and 

 as a consequence to Natural Selection, entailing divergence 

 of character and the extinction of less-improved forms. Thus, 

 from the war of nature, from famine and death, the most 

 exalted object which we are capable of conceiving, namely, 

 the production of the higher animals, directly follows." 1 



Since Darwin's time his theory of Natural Selection has 

 been tested in every conceivable way by succeeding biologists, 

 and it may be useful for us to know in what esteem it is held 

 at the present time. Vernon Kellogg briefly describes Dar- 

 winism, in biological language, as follows: "The exquisite 

 adaptation of the parts and functions of the animal and plant 

 as we can see it every day to our infinite admiration and 

 wonder, has all come to exist through the purely mechanical, 

 inevitable weeding out and selecting by nature (by environ- 

 mental determining of what may and may not live) through 

 uncounted generations in unreckonable time." 2 Darwinism 

 is "a certain rational, causo-mechanical (hence non-teleologic) 

 explanation of the origin of new species". 3 



In 'The Origin of Species' we have the main principles of 

 Darwinism. Darwin's later works are either modifications 

 or extensions of the fundamental principles here laid down. 

 But even these principles have not been allowed to go un- 

 challenged. On the one hand, Natural Selection is denied any 

 power whatever in the process of species-forming. On the 

 other hand, the effectiveness of the theory of the inheritance 

 of acquired characters is similarly denied. 4 From the con- 

 troversy that has prevailed for the past twenty-five years in 



^.C. p. 305. 



2 Vernon L. Kellogg, "Darwinism To-Day", Henry Holt & Co., 1908, 

 p. 15. 



3 O.C. p. 13. 

 KXC. Chs. 3-6. 



