Masterpieces of Science 



notwithstanding the ability and scientific skill 

 with which it has been supported. The course of 

 a true theory is very different, as may be well 

 seen by the progress of opinion on the subject of 

 natural selection. In less than eight years "The 

 Origin of Species " has produced conviction in the 

 minds of a majority of the most eminent living 

 men of science. New facts, new problems, new 

 difficulties as they arise are accepted, solved or 

 removed by this theory; and its principles are 

 illustrated by the progress and conclusions of 

 every well established branch of human knowl- 

 edge. It is the object of the present essay to 

 show how it has recently been applied to connect 

 together and explain a variety of curious facts 

 which had long been considered as inexplicable 

 anomalies. 



Perhaps no principle has ever been announced 

 so fertile in results" as that which Mr. Darwin 

 so earnestly impresses upon us, and which is 

 indeed a necessary deduction from the theory 

 of natural selection, namely — that none of the 

 definite facts of organic nature, no special organ, 

 no characteristic form or marking, no peculiar- 

 ities of instinct or of habit, no relations between 

 species or between groups of species — can exist, 

 but which must now be or once have been useful 

 to the individuals or races which possess them. 

 This great principle gives us a clue which we can 

 follow out in the study of many recondite phe- 

 nomena, and leads us to seek a meaning and a 

 purpose of some definite character in minutia) 

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