Chapter IV 



THE ORGANISM AND ITS CHEMISTRY 



Standpomt of the Discussion that of the Evolutionary 



Naturalist 



I3HYSIOLOGISTS and biochemists are not forced into 

 ^ contact with questions of organic evolution to any such 

 extent as are botanists and zoologists. Occupied as they 

 are in any particular investigation with relatively restricted 

 aspects of one or a few organisms, such matters as geogra- 

 phic distribution, geologic succession, abundance and variety 

 of individuals and species, adaptation, and so on, come to 

 their attention very little or not at all. But these are 

 exactly the problems with which the naturalist is occupied, 

 and they are at the same time the very building stones of 

 the evolution theory. This difference in interests and occu- 

 pations doubtless accounts for the fact that the great 

 evolutionists of history have been, without exception, natu- 

 ralists primarily. The three names that stand out with 

 mountain like conspicuousness among those who in modem 

 times have made the idea of evolution a household posses- 

 sion, Lamarck, Darwin, and Wallace, sufficiently illustrate 

 the point. These men were each botanist and zoologist in 

 almost equal degree and in the strictest sense. Their work 

 began out of doors with the vast riches of living plants 

 and animals, and the impetus from this source dominated all 

 they did. 



In the highly subdivided and specialized biological realm 

 of to-day, those who are trained in either botany or zoology 



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