350 Appendix A 



trial forms found in Australia. Professor Osborn has alluded 

 to the arboreal habits said to have been lately acquired by 

 Australian rabbits ; these and the similar modifications in 

 habits of West Indian rats are further examples of individual 

 adaptive modification which may well become the starting- 

 point (in the sense implied above) of specific variation led 

 by natural selection in the definite direction of more and 

 more complete adjustment to the necessities of arboreal life. 

 Although this conclusion seems to me to be clear and sound, 

 and the principles involved seem to constitute a substantial 

 gain in the attempt to understand the motive forces by which 

 the great progress of organic evolution has been brought about, 

 I cannot admit that the importance of natural selection is in 

 any way diminished. I do not believe that these important 

 principles form any real compromise between the Lamarckian 

 and Darwinian positions, in the sense of an equal surrender 

 on either side and the adoption of an intermediate position. 

 The surrender of the Lamarckian position seems to me com- 

 plete, while the considerations now advanced only confer added 

 significance and strength to the Darwinian standpoint. 



" I propose to devote the remainder of the time at my disposal 

 in support of the conclusion that the power of individual adap- 

 tation possessed by the organism forms one of the highest 

 achievements of natural selection, and cannot in any true 

 sense be considered as its substitute. Professor Baldwin and 

 Professor Lloyd Morgan thoroughly agree with this conclusion, 

 and have enforced it in their writings on organic selection. 

 The contention here urged is that natural selection works upon 

 the highest organisms in such a way that they have become 

 modifiable, and that this power of purely individual adaptability 

 in fact acts as the nurse by whose help the species, as the 

 above-named authorities maintain, can live through times in 

 which the needed inherent variations are not forthcoming, but 

 in part acts also as a substitute, not indeed for natural selection, 

 but for the ordinary operation by which the latter produces 

 change. In this latter case natural selection acts so as to 

 produce a plastic adaptable individual which can meet any of 



