206 ANNUAL REPORT SMITHSONIAN INSTITUTION, 19 34 



seemed to them logically necessary, and after they had been given 

 high-sounding names, usually of Greek derivation, these principles 

 seemed to be well-established realities. In addition to the four 

 principles mentioned above such terms as catagenesis, ergogenesis, 

 emphytogenesis, mnemogenesis, statogenesis, and many others of 

 similar sort were introduced. Such nominalism is not unknown in 

 evolutionary speculations even at present. 



On the other side I championed ^ the Weismannian view that (1) 

 acquired characters are not inherited, (2) that inherited characters 

 must be predetermined, but not preformed, in the germ cells, and 

 in particular in submicroscopic inheritance units, (3) that all heredi- 

 tary variations are caused by the action of extrinsic forces on the 

 germinal protoplasm, producing changes in its structure, rather than 

 upon developed organisms, and finally (4) that the only way of 

 breaking the deadlock between Lamarckians and Darwinians was by 

 means of experiment. In the light of subsequent events I think I 

 have no reason to regret my immature contribution to this sym- 

 posium. 



Professor Bailey's * philosophy was neither strictly Lamarckian nor 

 Darwinian, although in general it leaned to the former ; it was rather 

 sui generis and might be called Baileyan. He maintained that vari- 

 ability is the original law of organisms, that like no more produces 

 like than unlike, but that mutability is a fundamental and normal 

 law, while heredity or permanency is an acquired character. The 

 organism is shaped by its environment, and nature eliminates the non- 

 variable and favors the survival of the unlike. 



This account of a long forgotten program in the history of this 

 Society is useful merely as indicating some of the opinions and specu- 

 lations regarding the causes of evolution a generation ago. There 

 was a plethora of speculation and discussion and a paucity of proof. 

 In what follows I must beg the indulgence of those who are thor- 

 oughly familiar with the subject while I recount some of the main 

 points in the more recent developments in our knowledge of evolu- 

 tion. 



II 



With the beginning of the present century the study of evolution 

 entered upon a new era. Up to the year 1900 it had been based 

 largely upon observations and what were supposed to be logical 

 deductions. Keally students of evolution were dealing with prob- 

 abilities of a higher or lower order and no certainty could be 

 reached on such a basis. What seemed highly probable to one per- 



^ Proc. Amer. Philos. Soc, vol. 35, 1896. 

 * Idem. 



