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JOURNAL OF THE EOYAL HORTICULTURAL SOCIETY. 



fore, after the first twenty years, which Dr. Wallace allows for varying 

 in size and colour, they would be all alike. But twenty years is an 

 arbitrary number. The possibility is they begin to change in the first 

 generation. Plants certainly do so. 



The fact is that Darwin's two alternative explanations of the 

 Origin of Species are mutually exclusive. The origin of species hy 

 means of natural selection depends upon a chance appearance of one 

 or more among many variations, which may be in adaptation to, but 

 quite irrespective of, the environment. 



The Origin of Species by Response depends upon the immediate 

 appearance of adaptations in every individual, such being due to the 

 responsiveness of life to the " direct action of new conditions of life," 

 all the individuals varying alike with the same adaptation, and without 

 any selection whatever (Darwin). 



No facts, without the necessity of additional assumptions, have 

 ever proved the first to be true. 



Abundance of facts have proved by wide inductions, as well as by 

 experimental verification, that the latter is always the case. 



Dr. Wallace appears to try in some way to make the latter method 

 to be an extension of Darwin's theory " ; but this is impossible, from 

 the very conditions necessary, for Darwin shows that, if the results are 

 " . . . indefinite as required for natural selection," then they cannot 

 be " definite," and vice versa. Dr. Wallace says: " But a few years 

 ago an idea occurred independently to three biologists of a self-acting 

 principle in Nature which would be of such assistance to any species 

 in danger of extermination as, in some cases at all events, would 

 enable it to become adapted to the new conditions." 



Dr. Wallace continues to say that: It would, in fact, increase 

 the powers of natural selection." He takes as his illustration the 

 use of limbs, Lamarck's contention, and he applies it to the running 

 powers of animals, the better runners surviving by escaping their 

 enemies. He does not admit an heredity in such an acquired character ; 

 only " the quality of being improvable during life would be trans- 

 mitted." Why ** improvable " by inheritance, if the improvement of 

 an organ acquired during the life-time be not inherited; for there 

 would remain nothing but the capacity for improvement, inherent in 

 all organisms for life only? 



In Chapter XIV. we reach the most important development. It is 

 headed ' ' Birds and Insects : as Proofs of an Organising and Directive 

 Life-Principle." 



Dr. Wallace speaks of elements and their compounds as organic 

 products, and observes that " large numbers of them have been pro- 

 duced in the laboratory, but always by the use of other organic 

 products, not from the simple elements used by nature." f 



* Who these three may be the author does not tell lus; bul- tSir A. H. 

 Church saw the importarKie of what he called "Directivity" of life iii 1862; 

 Mr. James CroU that something must " determine " molecular motion in 1872. 

 M. Gonstantin and myself published books on' " Self -Adaptation " in 1888.. 

 though I first thought of it in 1869 ; and Warming said the same thing in 

 1892. t P. 292. 



