Variation and Natural Selection. 121 



process as natural selection is manifestly absurd. Lyell 

 was the necessary precursor of Darwin. Given, then, 

 increase and elimination throughout geological time, 

 natural selection is a logical necessity. No one who 

 adequately grasps the facts can now deny it. It is an 

 unquestionable factor in organic evolution. Whether it is 

 the sole factor, is quite another matter, and one we will 

 consider in the chapter on " Organic Evolution," 



