CHAPTER XIX 



THE RISE OF EVOLUTIONARY THOUGHT 



A CURRENT of evolutionary thought can be traced through 

 the literature dealing with organic nature from ancient times. 

 It began as a small rill among the Greek philosophers and 

 dwindles to a mere thread in the Middle Ages, sometimes 

 almost disappearing, but is never completely broken off. 

 Near the close of the eighteenth century it suddenly expands, 

 and becomes a broad and prevailing influence in the nine- 

 teenth century. Osborn, in his book, From the Greeks to 

 Darwin, traces the continuity of evolutionary thought from 

 the time of the Greek philosophers to Darwin. The ancient 

 phase, although interesting, was vague and general, and 

 may be dismissed without much consideration. After the 

 Renaissance naturalists were occupied with other aspects of 

 nature-study. They were at first attempting to get a knowl- 

 edge of animals and plants as a whole, and later of their 

 structure, their developments, and their physiology, before 

 questions of their origin were brought under consideration. 



Opinion before Lamarck. The period just prior to 

 Lamarck is of particular interest. Since Lamarck was the 

 first to give a comprehensive and consistent theory of evolu- 

 tion, it will be interesting to determine what was the state 

 of opinion just prior to the appearance of his writings. 

 Studies of nature were in such shape at that time that the 

 question of the origin of species arose, and thereafter it would 

 not recede. This was owing mainly to the fact that Ray and 

 Linnaeus by defining a species had fixed the attention of 



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