molten interior and a very thin crust, and in
no other way can the phenomena of geology be explained....--Yours very
truly,

ALFRED R. WALLACE.

* * * * *

TO SIR OLIVER LODGE

_Parkstone, Dorset. March 8, 1898._

My dear Sir,--My own opinion has long been--and I have many times given
reasons for it--that there is always an ample amount of variation in all
directions to allow any useful modification to be produced, very
rapidly, as compared with the rate of those secular changes (climate and
geography) which necessitate adaptation; hence no guidance of variation
in certain lines is necessary. For proof of this I would ask you to look
at the diagrams in Chapter III. of my "Darwinism," reading the
explanation in the text. The proof of such constant indefinite
variability has been much increased of late years, and if you consider
that instead of tens or hundreds of individuals, Nature has as many
thousands or millions to be selected from, every year or two, it will be
clear that the materials for adaptation are ample.

Again, I believe that the time, even as limited by Lord Kelvin's
calculations, is ample, for reasons given in Chapter X., "On the Earth's
Age," in my "Island Life," and summed up on p. 236. I therefore consider
the difficulty set forth on p. 2 of the leaflet you send is not a real
one. To my mind, the development of plants and animals from low forms of
each is fully explained by the variability proved to exist, with the
actual rapid multiplication and Natural Selection. For this no other
intellectual agency is required. The problem is to account for the
infinitely complex constitution of the material world and its forces
which rendered living organisms possible; then, the introduction of
consciousness or sensation, which alone rendered the animal world
possible; lastly, the presence in man of capacities and moral ideas and
aspirations which could not conceivably be produced by variation and
Natural Selection. This is stated at p. 473-8 of my "Darwinism," and is
also referred to in the article I enclose (at p. 443) and which you need
not return.

The subject is so large and complex that it is not to be wondered so
many people still maintain the insufficiency of Natural Selection,
without having really mastered the facts. I could not, therefore, answer
your question without going into some detail and giving references....
--Believe me yours very truly,

ALFRED R. WAL