PRESIDENTIAL ADDRESS. 69 



Wallace-'- makes the following remarks on this point: "Mr. 

 Wallace's contention that the mathematical and artistic fac- 

 ulties of man have not been developed under the law of 

 natural selection must in large part be conceded .... their 

 sudden and rapid development to a very much higher level in 

 civilized communities cannot be traced to the struggle between 

 man and man. It does not however follow that, because 

 natural selection will not account for these extraordinary 

 developments of the human brain, therefore we must have 

 recourse to the assumption of supernatural agencies. Mr. 

 Wallace seems so much convinced of the capability of the 

 principle of natural selection, that when it breaks down as an 

 explanation he loses faith in all natural cause, and has recourse 

 to a metaphysical assumption.'' But Prof. Ray I^ankester, 

 estopped by his consistent defense of Weismann's views, is 

 obliged to ignore the obvious explanation that the intense 

 exercise of these faculties, impressing itself profoundly upon 

 the plastic brain substance and reacting upon the germs of 

 posterity has been transmitted to descendants through centu- 

 ries of developing civilization, and he has recourse to his 

 doctrine of "sports" and to Gulick's law of "divergent 

 evolution" which is nearly the same as what I have called 

 "fortuitous variation." 



But we need not confine ourselves exclusively to the mental 

 qualities. A favorite illustration of the efficacy of selection is 

 the progress which has been secured in the fleetness and other 

 desired qualities in horses, and Mr. Wallace, in the Fortnightly 

 Review for September 1890, has instituted a contrast between 

 what would result in this direction from a system of intelligent 

 breeding and one of mere feeding and exercise. His illustra- 

 tion is thoroughly unfair, even ridiculous, since he does not 



* Nature, Vol. XL,, Oct. 10, 1S89, pp. 569-570. 



