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ANNALS NEW YORK ACADEMY OF SCIENCES 
of thought, attributed to that influence a potent evolutionary effect. If, 
as I pointed out in my presidential address of last year, he had persistently 
maintained the position that natural selection could and would operate upon 
any kind or degree of variation, he need not to have felt troubled as to its 
sufficiency as a true cause of evolution. Assuming that the action of the 
environment can bring about diversity of characters or qualities, the determi¬ 
nation of the survival of the fittest under any given circumstances does not 
depend upon the way in which the diverse forms arose. In this matter 
Darwin held a much stronger position than Lamarck, for, as I have already 
said, Lamarck, after attempting an explanation of the origin of variation, 
had no means of showing why a group of organisms varying in a certain direc¬ 
tion should be perpetuated to the exclusion of other forms which, as far as his 
theory provided ground for a judgment, ought, under the same conditions, 
to vary in the same direction and thus to acquire the same means of meeting 
adverse circumstances. 
It is not necessary in order to maintain the supremacy of Darwin as the 
establisher of the evolution theory to contend that he and Lamarck had no 
ideas in common. They were both under the necessity of making use of 
the facts of nature as they were respectively able to discover them, and it 
would have been more than strange if, as working naturalists, they had not 
had common knowledge of many generalizations which were obviously im¬ 
portant in any argument for evolution. The differences between them, upon 
which we are obliged to found our judgment of their relative merits, are not 
so much in the mere employment of certain factors as in the emphasis laid 
upon them and the positions given them in the general logical scheme, al¬ 
though, in the final analysis, it will appear that Darwin’s introduction of the 
fascinating and satisfying doctrine of natural selection and its extension to 
the vegetable kingdom was the weight that turned the scales of opinion 
towards the acceptance of a theory of universal evolution. As I have already 
said, Lamarck could not have been an evolutionist without believing in the 
mutability of species, in some form, but he did not convince the world of the 
truth of mutability, because he was unable to point to its real cause. He 
refers occasionally to the selection practiced by breeders as evidence that 
variation may minister to need but fails to carry the process over into nature 
as a factor in general evolution. He was aware that because animals devour 
one another, the largest and strongest destroy the smaller and the weaker, 
but he never fully grasped the significance of the survival of those species 
best fitted to their conditions of life, nor had he the faintest idea that struggle 
for existence and selection of the best adapted might be the basis of evolution 
in the plant world. This fact we must not lose sight of, for, whatever La¬ 
marck may have founded, according to the claims of his adherents, he cer- 
