opposed. Bates himself could
never make up his mind to accept it. As the Fellows were walking out
of the meeting at which Professor Meldola explained the hypothesis, an
eminent entomologist, now deceased, was heard to say to Bates: "It's a
case of save me from my friends!" The new ideas encountered and still
encounter to a great extent the difficulty that the theory of Bates had
so completely penetrated the literature of natural history. The present
writer has observed that naturalists who have not thoroughly absorbed
the older hypothesis are usually far more impressed by the newer
one than are those whose allegiance has already been rendered. The
acceptance of Natural Selection itself was at first hindered by
similar causes, as Darwin clearly recognised: "If you argue about the
non-acceptance of Natural Selection, it seems to me a very striking fact
that the Newtonian theory of gravitation, which seems to every one now
so certain and plain, was rejected by a man so extraordinarily able as
Leibnitz. The truth will not penetrate a preoccupied mind." (To Sir J.
Hooker, July 28, 1868, "More Letters", I. page 305. See also the letter
to A.R. Wallace, April 30, 1868, in "More Letters" II. page 77, lines
6-8 from top.)

There are many naturalists, especially students of insects, who appear
to entertain an inveterate hostility to any theory of mimicry. Some of
them are eager investigators in the fascinating field of geographical
distribution, so essential for the study of Mimicry itself. The changes
of pattern undergone by a species of Erebia as we follow it over
different parts of the mountain ranges of Europe is indeed a most
interesting inquiry, but not more so than the differences between e.g.
the Acraea johnstoni of S.E. Rhodesia and of Kilimanjaro. A naturalist
who is interested by the Erebia should be equally interested by the
Acraea; and so he would be if the student of mimicry did not also
record that the characteristics which distinguish the northern from
the southern individuals of the African species correspond with the
presence, in the north but not in the south, of certain entirely
different butterflies. That this additional information should so
greatly weaken, in certain minds, the appeal of a favourite study, is a
psychological problem of no little interest. This curious antagonism is
I believe confined to a few students of insects. Those naturalists who,
standing rather farther off, are able to see the beari