CHAPTER n 



HISTORICAL ACCOUNT OF THE DEVELOPMENT OF THE 



EVOLUTION THEORY 



The chief sources of material for the present chapters are: Osborn's 

 From the Greeks to Darwin 1 and Judd's The Coming of Evolution.* 



Professor Osborn studies the evolution of the evolution idea as a 

 biologist would investigate the evolution of a group of species, using 

 all of the available sources of evidence at his disposal. The fragments 

 of ancient writing and the crude imaginings of early natural philoso- 

 phers are the fossils of the evolution idea, many of them ancestors 

 of modern principles; fragments of ancient or discarded ideas that 

 still persist, though irrelevant to modern thought, are the vestigial 

 structures that proclaim kinship between the past and the present; 

 parallelisms between the development of ideas in the minds of inde- 

 pendent thinkers do not prove plagiarism, but indicate common 

 descent from the same ancestral ideas. 



This whole history is an important chapter in the story of human 

 evolution in general, for it deals with the evolution of a characteristic 

 human faculty — that of appreciating the broad relations that exist 

 between the past and the present. This faculty has evolved as truly 

 as has an organic system such as the nervous system, and is unques- 

 tionably closely bound up with the latter. 



The evolution theory is a vast fabric of interrelated and inter- 

 dependent facts and principles. The fabric has been gradually woven 

 out of separate threads and now stands strong though flexible, with 

 strands reaching into all sciences and tending to unify all science. 



It was only after the lesser ideas came to be clearly apprehended 

 that it was possible for the master minds of Lamarck and of Darwin to 

 weave them together into a consistent fabric and to bring the facts 

 together under the one great conception, that of organic evolution. 

 Classification was a science, comparative anatomy had made much 

 progress, the principles of embryology were fairly well understood, 



1 II. F. Osborn, From the Greeks to Darwin (The Macmillan Company, 1908). 

 2 John W. Judd, The Coming of Evolution (Cambridge University Press, 1911J. 



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