IV 



EVOLUTION AS A NATURAL PROCESS 



THE purpose of the discussions up to this point has 

 been to present the reasons drawn from the principal 

 classes of zoological facts for believing that living 

 things have transformed naturally to become what they 

 now are. Even if it were possible to make an ex- 

 haustive analysis of all of the known phenomena of 

 animal structure, development, and fossil succession, 

 the complete bodies of knowledge could not make the 

 evolutionary explanation more real and evident than 

 it is shown to be by the simple facts and principles 

 selected to constitute the foregoing outline. We have 

 dealt solely with the evidences as to the fact of evolu- 

 tion; and now, having assured ourselves that it is 

 worth while to so do, we may turn to the intelligible 

 and reasonable evidence found by science which proves 

 that the familiar and everyday " forces" of nature are 

 competent to bring about evolution if they have 

 operated in the past as they do to-day. Investigation 

 has brought to light many of the subsidiary elements 

 of the whole process, and these are so real and obvious 

 that they are simply taken for granted without a 

 suspicion on our part of their power until science 

 directs our attention to them. 



For one reason or another, those who take up this 



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