1896.] A New Factor in Evolution. 541 
But these two influences furnish a double resort against Neo- 
Lamarkism. And I do not see anything in the way of con- 
sidering the fact of Organic Selection, from which both these 
resources spring, as being a sufficient supplement to the prin- 
ciple of natural selection. The relation which it bears to 
natural selection, however, is a matter of further remark be- 
low (V). 
“ We may say, therefore, that there are two great kinds of 
influence, each in a sense hereditary; there is natural heredity 
by which variations are congenitally transmitted with original 
endowment, and there is ‘social heredity’ by which functions 
socially acquired (i. e., imitatively, covering all the conscious 
acquisitions made through intercourse with other animals) are 
also socially transmitted. The one is phylogenetic ; the other 
ontogenetic. But these two lines of hereditary influence are 
not separate nor uninfluential on each other. Congenital varia- 
tions, on the one hand, are kept alive and made effective by 
their conscious use for intelligent and imitative adaptations in 
the life of the individual; and, on the other hand, intelligent 
and imitative adaptations become congenital by further prog- 
ress and refinement of variation in the same lines of function 
as those which their acquisition by the individual called into 
play. But there is no need in either case to assume the 
Lamarkian factor ” (ref. 4). 
“The only hindrance that I see to the child’s learning every- 
thing that his life in society requires would be just the thing 
that the advocates of Lamarkism argue for—the inheritance of 
acquired characters. For such inheritance would tend so to 
bind up the child’s nervous substance in fixed forms that he 
would have less or possibly no unstable substance left to learn 
anything with. So, in fact, it is with the animals in which 
instinct is largely developed; they have no power to learn 
anything new, just because their nervous systems are not in 
the mobile condition represented by high consciousness. They 
have instinct and little else ” (ref. 3). 
IV. 
The Process of Organic Selection—So far we have been dealing 
exclusively with facts. By recognizing certain facts we have 
