194 HOLISM AND EVOLUTION chap. 



record as well as with the facts of geographical distribution, 

 which he looked upon as the keystone to the laws of life. 

 No wonder that the appeal of Darwin's theory proved 

 irresistible and its effect crushing on all the older points of 

 view. The triumph of Darwin's splendid vision of Evolution 

 seemed complete. 



Then the second phase of Darwinism began, with the 

 detailed search for the methods and mechanism of Variation 

 and with the venue shifted from the ample range of Nature 

 to the research laboratory of Genetics. First Weismann 

 negatived the inheritance of acquired characters, and of 

 modifications due to use or disuse or other environmental 

 conditions operating on the individual life. Only the 

 accidental germinal variations, and none of the moulding 

 effects of the environment on the individual, could avail in 

 the building up of the new species. Then De Vries came 

 forward and largely eliminated small ordinary variations 

 from the account, and thus practically confined progress to 

 mutations. Finally, the experimental Mendelians or Gene- 

 ticists appeared, and through their researches and experi- 

 ments appeared to confine Evolution to the interchange, 

 the combinations and permutations of definite existing unit 

 characters. The combined effect of these three advances 

 on the Darwinian theory might appear largely destructive 

 of Darwinism itself. If, following the Mendelians, we 

 hold that the interchange of definite pre-existing unit char- 

 acters is all there is in the process of Evolution, advance 

 becomes impossible and creative Evolution disappears. 

 If, according to De Vries, accidental mutation is in a large 

 measure all there is for Natural Selection to work on, the 

 advance becomes indeed a most precarious affair, instead 

 of that steady, continuous, delicate process which has been 

 going on through the geological ages. If, according to Weis- 

 mann, modifications from use and disuse and similar causes 

 have no survival value and are inoperative in the forma- 

 tions of new species, it becomes most difficult to under- 

 stand the universal close-fitting adaptations of species to 

 their conditions of life. For there is nothing in common 



