208 UNIVERSITY OF MISSOURI BULLETIN 



In order to gain an intelligent understanding of the pres- 

 ent-day problems of evolution and heredity as they appear in 

 the light of modern experimental research, it is essential to 

 view them through the perspective of the past, and, accord- 

 ingly, I shall first outline — but very briefly — the more significant 

 facts in the history of evolutionary thought in the field of biol- 

 ogy, before attempting to speak of some of the results and con- 

 clusions which have been reached in recent years; for, as the 

 views which we now hold concerning organic descent and 

 hereditary relationships are themselves the outcome of a long 

 development, we cannot adequately consider the present status 

 of the subject apart from its historical setting. 



FROM THE GREEKS TO DARWIN. 



The essence of the idea of organic evolution, or the doc- 

 trine of the gradual development of organisms, may be traced 

 far back in the records of thought to the early Greek philos- 

 ophers, in whom — especially in Empedocles and Aristotle — 

 we find the first vague premonition of the genetic conception 

 of the origin of living things. 



The fundamental groundwork thus established by the 

 Greeks remained almost untouched for centuries, and, when 

 interest was reawakened in the problem of the origin of or- 

 ganic forms, it was due, not to the early naturlists, but to 

 the philosophers that attention was directed again in the track 

 of evolutionary thought. Although more or less direct con- 

 tributions were made to the foundations of evolution by various 

 philosophers of the seventeenth and eighteenth centuries, men- 

 tion here must be confined to Maupertuis (1698-1759) whose 

 views are for us of the greatest interest and significance. A 

 pronounced advocate of evolution and clearly recognized as 

 such by his contemporaries, he is especially noteworthy as 

 having not only suggested a theory of heredity, but as having 

 been the first to emphasize the fundamental importance of 



