olute distinctness of the parents.

I have been reading with great pleasure Mr. Bentham's last admirable
address (216/1. "Proc. Linn. Soc." 1867-8, page lvii.), in which he so
well replies to the gross misstatements of the "Athenaeum;" and also
says award in favour of pangenesis. I think we may now congratulate you
on having made a valuable convert, whose opinions on the subject, coming
so late and being evidently so well considered, will have much weight.

I am going to Norwich on Tuesday to hear Dr. Hooker, who I hope will
boldly promulgate "Darwinism" in his address. (216/2. Sir Joseph
Hooker's Presidential Address at the British Association Meeting.) Shall
we have the pleasure of seeing you there?

I am engaged in negociations about my book.

Hoping you are well and getting on with your next volumes.

(216/3. We are permitted by Mr. Wallace to append the following note
as to his more recent views on the question of Natural Selection and
sterility:--

"When writing my "Darwinism," and coming again to the consideration
of this problem of the effect of Natural Selection in accumulating
variations in the amount of sterility between varieties or incipient
species twenty years later, I became more convinced, than I was when
discussing with Darwin, of the substantial accuracy of my argument.
Recently a correspondent who is both a naturalist and a mathematician
has pointed out to me a slight error in my calculation at page 183
(which does not, however, materially affect the result), disproving the
'physiological selection' of the late Dr. Romanes, but he can see no
fallacy in my argument as to the power of Natural Selection to increase
sterility between incipient species, nor, so far as I am aware, has any
one shown such fallacy to exist.

"On the other points on which I differed from Mr. Darwin in the
foregoing discussion--the effect of high fertility on population of a
species, etc.--I still hold the views I then expressed, but it would be
out of place to attempt to justify them here."

A.R.W. (1899).)

LETTER 217. TO C. LYELL. Down, October 4th [1867].

With respect to the points in your note, I may sometimes have expressed
myself with ambiguity. At the end of Chapter XXIII., where I say that
marked races are not often (you omit "often") produced by changed
conditions (217/1. "Hence, although it must be admitted that new
conditions of life do sometimes definitely affect organic beings, it
may be doubted whe