62 BIOLOGICAL SOCIETY OF WASHINGTON. 



arckism proper, while at the same time it is an effective 

 answer to a large part of the argument directed against the 

 transmission of functionally acquired characters. 



Professor Osliorn has probably made the most of the argu- 

 ment from paleontology, and it must be left to the candid 

 judgment of scientific men to sa}' whether the case is made 

 out. It is of course always possible to saj- that the initial 

 variations which inaugurated each new adaptation were 

 merely accidental and were seized upon b}' natural selection, 

 and it is to a large extent a question of faith in the universal 

 efficacy of that theory ; or rather a question in candid minds 

 of the relative reasonableness of that view and of the view 

 which ascribes a considerable part of this initial variation to 

 functionall}^ produced modifications transmitted by heredity. 



It would be unjust to this Societ^^ to omit in an enumera- 

 tion, however imperfect, of the American defenders of the 

 transmissibility of acquired modifications, your former presi- 

 dent Prof. W. H. Dall, whose protracted studies in inverte- 

 brate paleontolog}-, conchology, and especially the molluscan 

 life of the deep sea have led him to a full accord with other 

 American workers as regards questions of this class. In his 

 presidential addresses, not to speak of earlier papers, he has 

 emphasized the molding influence of the environment upon 

 the plastic organisms with which he is most familiar, and 

 during the past year he has contributed to the Society one 

 paper-' dealing directly with the Neo-Darwinian claims, in 

 which the case is as clearly presented as it has been by an}- 

 other writer, and in man}- respects in an entirely new light. 



For myself, I cannot claim to have made any direct contri- 

 bution to this specific subject. I have been deeply interested 



*Oii Dynamic Influences in PA'olulion, l)y W. H. Dall. Proc. Biol. 

 Soc. Wash., Vol. VI, pp. i-io. 



