XV] Natural Selection 289 



may be reached, it is here. The conception of Evolution as 

 proceeding through the gradual transformation of masses 

 of individuals by the accumulation of impalpable changes 

 is one that the study of genetics shows immediately to be 

 false. Once for all, that burden so gratuitously undertaken 

 in ignorance of genetic physiology by the evolutionists of 

 the last century may be cast into oblivion. For the facts 

 of heredity and variation unite to prove that genetic varia- 

 tion is a phenomenon of individuals. Each new character 

 is formed in some germ-cell of some particular individual, 

 at some point of time. More we cannot assert. That the 

 variations are controlled by physiological law, we have now 

 experimental proof; but that this control is guided ever so 

 little in response to the needs of Adaptation there is not 

 the smallest sign. If chance variation was an improbable 

 source of the adapted diversity which living things exhibit, 

 the improbability remains, undiminished perhaps, but cer- 

 tainly not increased, by the recognition of that control. 



There is also nothing in Mendelian discovery which 

 runs counter to the cardinal doctrine that species have 

 arisen "by means of Natural Selection, or the preservation 

 of favoured races in the struggle for life," to use the defini- 

 tion of that doctrine inscribed on the title of the Origin. 

 By the arbitrament of Natural Selection all must succeed 

 or fail. Nevertheless the result of modern inquiry has 

 unquestionably been to deprive that principle of those 

 supernatural attributes with which it has sometimes been 

 invested. The scope of Natural Selection is closely limited 

 by the laws of variation. How precise and specific are 

 those laws we are only beginning to perceive. In the light 

 of the new knowledge various plausible, but frequently 

 unsatisfying, suggestions put forward, especially by Wallace, 

 Weismann, and their followers, as probable accounts of 

 evolutionary progress, must be finally abandoned. It 

 cannot in candour be denied that there are passages in the 

 works of Darwin which in some measure give countenance 

 to these abuses of the principle of Natural Selection, but 

 I rest easy in the certainty that had Mendel's paper come 

 into his hands, those passages would have been immediately 



revised. 



For Darwin, indeed, Mendelism would have provided 



B. H. 19 



