THE 



AMERICAN NATURALIST 



Vol. XL VII February, 1918 No. 554 



ADAPTATION THROUGH NATURAL SELECTION 

 AND ORTHOGENESIS 1 



PROFESSOR MAYNARD M. METCALF 

 Oberlin College 



Mr. President, Members of the Society, and Friends: 

 When the president of our society, Professor Conklin, 

 asked me to open this discussion, he suggested that I 

 speak in advocacy of natural selection as the dominant 

 factor in adaptation, saying that several speakers would 

 follow who would attack this conception. As I under- 

 stand it, a paper in advocacy of natural selection is 

 desired not so much that it may be a target at which fol- 

 lowing speakers may direct their shafts, as that this 

 conception may not stand without defenders. 



It involves some temerity to speak to an audience of 

 American naturalists upon natural selection, for the con- 

 ception is more than a decade old. It dates even from 

 the dark ages of the middle of the last century, and we 

 naturalists, like the Athenians to whom Paul spoke, are 

 continually seeking some new thing. I can not even, as 

 DeVries and Bateson in the case of Mendel's principles, 

 claim the honor of a re-discoverer, for through all the 

 years since its first promulgation the conception of nat- 

 ural selection has been constantly to the fore and has been 

 discussed and re-discussed until many, I fear, have 

 wearied of it, and for this very reason may be ready to 

 give too undiscriminating welcome to other conceptions 

 that seek to supplant the old idea. 



1 Read at the Symposium on Adaptation at the meeting of the American 

 Society of Naturalists, Cleveland, January 2, 1913. 



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