Chapter VII 

 THE GROWTH OF BIOLOGICAL IDEAS * 



The sciences did not develop in a logical order. Without 

 previous advances in the physical sciences, biology could 

 make only limited progress. It was, however, one of the 

 first sciences to which serious study was devoted; whereas 

 chemistry, as we have seen (page 119), made very little ad- 

 vance until toward the end of the eighteenth century. 

 Twenty-two centuries before, in the fourth century B.C., 

 Aristotle had already made considerable progress in the in- 

 vestigation of animal life. He was an acute natural his- 

 torian with a particular interest in the study of reproduc- 

 tion and development. In the following centuries biology 

 continued to be studied and taught in the museum at Alex- 

 andria. The store of biological knowledge continued to 

 grow until the time of Galen, in the second century after 

 Christ. Galen studied in Alexandria and his native Asia 

 Minor, and later in Rome. He was essentially a medical 

 man, but he made important studies on the anatomy and 

 physiology of various mammals. With his death the helix 

 of history had completed a revolution, and biology sank 

 back into insignificance. 



It is true that knowledge of the work of Aristotle and Galen 

 was kept just alive during the long period of the Dark Ages, 

 but there was little or no progress. When the study of the 

 ancient authors ^vas revived, they came to be regarded as 



* The reader who requires a textbook treatment of the history of 

 biology should use one or more of the following standard works: 

 W. A. Locy, Biology and Its Makers, New York, Henry Holt, 1915. 

 E. Nordenski()ld, The History of Biology, London, Kegan Paul, 1929. 

 C. Singer, A Short History of Biology, Oxford, Clarendon Press, 1931. 



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