distinct as they now generally are
on islands.

LETTER 115. TO H.G. BRONN. Down, October 5th [1860].

I ought to apologise for troubling you, but I have at last carefully
read your excellent criticisms on my book. (115/1. Bronn added critical
remarks to his German translation of the "Origin": see "Life and
Letters," II., page 279.) I agree with much of them, and wholly with
your final sentence. The objections and difficulties which may be urged
against my view are indeed heavy enough almost to break my back, but it
is not yet broken! You put very well and very fairly that I can in
no one instance explain the course of modification in any particular
instance. I could make some sort of answer to your case of the two rats;
and might I not turn round and ask him who believes in the separate
creation of each species, why one rat has a longer tail or shorter ears
than another? I presume that most people would say that these characters
were of some use, or stood in some connection with other parts; and if
so, Natural Selection would act on them. But as you put the case,
it tells well against me. You argue most justly against my question,
whether the many species were created as eggs (115/2. See Letter 110.)
or as mature, etc. I certainly had no right to ask that question.
I fully agree that there might have been as well a hundred thousand
creations as eight or ten, or only one. But then, on the view of eight
or ten creations (i.e. as many as there are distinct types of structure)
we can on my view understand the homological and embryological
resemblance of all the organisms of each type, and on this ground almost
alone I disbelieve in the innumerable acts of creation. There are only
two points on which I think you have misunderstood me. I refer only to
one Glacial period as affecting the distribution of organic beings; I
did not wish even to allude to the doubtful evidence of glacial action
in the Permian and Carboniferous periods. Secondly, I do not believe
that the process of development has always been carried on at the same
rate in all different parts of the world. Australia is opposed to such
belief. The nearly contemporaneous equal development in past periods I
attribute to the slow migration of the higher and more dominant forms
over the whole world, and not to independent acts of development in
different parts. Lastly, permit me to add that I cannot see the force
of your objection, that nothing is effected until th