446 KINSHIP AND ADAPTATION 
indistinguishable from wild plants of the same species. But 
might not very long subjection to changed conditions finally 
fix an acquired character? Possibly, and it should be said 
that the botanical evidence is perhaps more favorable to this 
view than the zodlogical; but if the facts can be explained 
without relying upon suppositions hardly possible to verify, 
we may build upon a safer foundation. 
167. Selected adaptations. Dissatisfaction with La- 
marck’s explanation of modification through acquirement, 
deterred most of his contemporaries from accepting the theory 
of evolution, and it was not until Charles Darwin and Alfred 
Russel Wallace offered an explanation based upon acknowl- 
edged facts that evolutionism was welcomed at all widely 
by scientific thinkers. The new doctrine is generally known 
as Darwinism, because Darwin’s contributions in support of 
it were most extensive and important, although both Darwin 
and Wallace, working quite independently, came to sub- 
stantially the same conclusions, and announced them at the 
same meeting of the Linnzan Society of London in 1858. 
Darwin felt that the problem of how one species changes 
into another might best be attacked by studying the modi- 
fications which plants and animals undergo when domesti- 
cated. We have already seen (page 126) how much has been 
accomplished with cultivated plants by artificial selection,— 
farmers taking their seed from those individuals which please 
them best and continuing to pick out for propagation year 
after year the plants which show most fully those most de- 
sirable features. Here it would seem as if hereditary pecul- 
iarities were surely depended upon, and that the most strik- 
ing departures from an original form represented the sum of 
many small differences in one direction accumulated through 
successive generations by inheritance. Darwin reasoned 
that if it could be shown that plants and animals in nature 
were continually subjected to agencies which favored the 
propagation of individuals possessed of slight hereditary 
peculiarities contributing to their welfare, the most perfect 
adaptations would be accounted for and the origin of species 
scientifically explained. 
What natural agencies can be supposed to exert a selective 
