increase in numbers, there would be no tendency to the preservation and
accumulation of such variations--i.e. to the formation of a new race. As
the proboscidean group seems to be from utterly unknown causes a failing
group in many parts of the world, I should not have anticipated the
formation of new races.

You make important remarks versus Natural Selection, and you will perhaps
be surprised that I do to a large extent agree with you. I could show you
many passages, written as strongly as I could in the "Origin," declaring
that Natural Selection can do nothing without previous variability; and I
have tried to put equally strongly that variability is governed by many
laws, mostly quite unknown. My title deceives people, and I wish I had
made it rather different. Your phyllotaxis (143/3. Falconer, page 80:
"The law of Phyllotaxis...is nearly as constant in its manifestation as any
of the physical laws connected with the material world.") will serve as
example, for I quite agree that the spiral arrangement of a certain number
of whorls of leaves (however that may have primordially arisen, and whether
quite as invariable as you state), governs the limits of variability, and
therefore governs what Natural Selection can do. Let me explain how it
arose that I laid so much stress on Natural Selection, and I still think
justly. I came to think from geographical distribution, etc., etc., that
species probably change; but for years I was stopped dead by my utter
incapability of seeing how every part of each creature (a woodpecker or
swallow, for instance) had become adapted to its conditions of life. This
seemed to me, and does still seem, the problem to solve; and I think
Natural Selection solves it, as artificial selection solves the adaptation
of domestic races for man's use. But I suspect that you mean something
further,--that there is some unknown law of evolution by which species
necessarily change; and if this be so, I cannot agree. This, however, is
too large a question even for so unreasonably long a letter as this.