ists
before Darwin's day, though no one (except Herbert Spencer in the
psychological domain (1855)) had come near him in precision and
thoroughness of inquiry.

(III) In the third place, Darwin contributed largely to a knowledge of
the factors in the evolution-process, especially by his analysis of what
occurs in the case of domestic animals and cultivated plants, and by
his elaboration of the theory of Natural Selection, which Alfred Russel
Wallace independently stated at the same time, and of which there had
been a few previous suggestions of a more or less vague description.
It was here that Darwin's originality was greatest, for he revealed to
naturalists the many different forms--often very subtle--which natural
selection takes, and with the insight of a disciplined scientific
imagination he realised what a mighty engine of progress it has been and
is.

(IV) As an epoch-marking contribution, not only to Aetiology but to
Natural History in the widest sense, we rank the picture which
Darwin gave to the world of the web of life, that is to say, of
the inter-relations and linkages in Nature. For the Biology of the
individual--if that be not a contradiction in terms--no idea is more
fundamental than that of the correlation of organs, but Darwin's most
characteristic contribution was not less fundamental,--it was the idea
of the correlation of organisms. This, again, was not novel; we find
it in the works of naturalist like Christian Conrad Sprengel, Gilbert
White, and Alexander von Humboldt, but the realisation of its full
import was distinctively Darwinian.

AS REGARDS THE GENERAL IDEA OF ORGANIC EVOLUTION.

While it is true, as Prof. H.F. Osborn puts it, that "'Before and after
Darwin' will always be the ante et post urbem conditam of biological
history," it is also true that the general idea of organic evolution
is very ancient. In his admirable sketch "From the Greeks to Darwin"
("Columbia University Biological Series", Vol. I. New York and London,
1894. We must acknowledge our great indebtness to this fine piece of
work.), Prof. Osborn has shown that several of the ancient philosophers
looked upon Nature as a gradual development and as still in process of
change. In the suggestions of Empedocles, to take the best instance,
there were "four sparks of truth,--first, that the development of life
was a gradual process; second, that plants were evolved before animals;
third, that imperfect forms were gradually repl