PRESIDENTIAL ADDRESS. 61 



dence from paleontology is particularly striking in this respect. 

 A volume of Professor Cope's memoirs was published in 1887 

 under the title of " The Origin of the Fittest," by which title 

 he aimed to express the idea of the cause or origin of modifi 

 cations that have taken place, as distinguished from Darwin's 

 explanation of the laws of transformation based on the assump 

 tion of such modifications taken as simple facts of observa 

 tion. Both methods are scientific, but the former carries us 

 one step nearer to the true origin of things. 



More recently Prof. H. F, Osborn of Princeton College has 

 taken up this line of argument and presented it in several 

 memoirs in which he has attempted a direct answer to Weis- 

 m arm's charge that no facts have been furnished in support of 

 the transmission of acquired characters.* 



In the latest of these papers, that read before the Society of 

 Naturalists in Boston December 31, 1890, not yet published, 

 but of which an advance copy was kindly sent me by him, he 

 has stated the whole problem with a judicial fairness which all 

 must admire, and with a keenness of analysis which places 

 him in the front rank of modern biological thinkers. 



Perhaps the most important contribution which he has made 

 to the subject is that in which he shows that "the main trend 

 of variation is determined not by the transmission of the full 

 adaptive modifications themselves, as Lamarck supposed, but 

 of the disposition to adaptive atrophy or hypertrophy at cer 

 tain points." 



This principle goes farther than any other that has been 

 brought forward to differentiate Neo-Lamarckism from Lam- 



* Proceedings of the American Association for the Advancement of 

 Science, Vol. XXXVIII, 1889 (Toronto), pp. 273-276. 



British Association Report, 1889 (Newcastle-upon-Tyne), p. 621 ; 

 Nature, Vol. XLI, Jan. 9, 1890, p. 227. 



American Naturalist, Vol. XXIII, July, 1889, pp. 561-566. 



