II. 



NEO-LAMARCKISM AND NEO- DARWINISM.' 



It is difficult to accept the hj'pothesis of organic 

 evolution in the abstract. In the first place, there must 

 be some reason for the operation of a law of transform- 

 ation or development; and this is found in the ever- 

 changing physical or external conditions of existence, 

 which are more or less opposed to established organisms. 

 And it may also be said that the very fact of the increase 

 of organisms through multiplication must impose new 

 conditions of competition upon every succeeding gene- 

 ration. Again, it is necessary to conceive of some meaiis 

 or machinery by which the process of evolution is carried 

 forward. It was long known that all species vary, that 

 is, that no two individuals in nature are exactly alike; 

 yet there was lacking anj' hypothesis to show either why 

 these varieties appear or how it is that some become per- 

 manent and some do not. The first scientific explanation 

 of the process of evolution was that made in 1809 by the 

 now famous Lamarck. He saw two factors which, he 

 thought, were concerned in the transformation of 

 species — the habitat and the habit. The habitat is the 

 condition in which the organism lives, the environment. 

 This environment, subject to change with every new 

 individual, calls for new habits to adapt the organism 

 to the new needs — inducing greater exercise of some 



•Extract from an address before the Philosophical Club of Cornell University. 

 Printed in American Naturalist, xxviii. 661 (August, 1894) . 



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