t joy he has got surprisingly better...I
had not heard of your botanical appointment (22/1. Sir Joseph was
appointed Botanist to the Geological Survey in 1846.), and am very glad
of it, more especially as it will make you travel and give you change
of work and relaxation. Will you some time have to examine the Chalk and
its junction with London Clay and Greensand? If so our house would be
a good central place, and my horse would be at your disposal. Could you
not spin a long week out of this examination? it would in truth delight
us, and you could bring your papers (like Lyell) and work at odd times.
Forbes has been writing to me about his subsidence doctrines; I wish I
had heard his full details, but I have expressed to him in my ignorance
my objections, which rest merely on its too great hypothetical basis;
I shall be curious, when I meet him, to hear what he says. He is
also speculating on the gulf-weed. I confess I cannot appreciate his
reasoning about his Miocene continent, but I daresay it is from want of
knowledge.

You allude to the Sicily flora not being peculiar, and this being caused
by its recent elevation (well established) in the main part: you will
find Lyell has put forward this very clearly and well. The Apennines
(which I was somewhere lately reading about) seems a very curious case.

I think Forbes ought to allude a little to Lyell's (22/2. See Letter
19.) work on nearly the same subject as his speculations; not that I
mean that Forbes wishes to take the smallest credit from him or any man
alive; no man, as far as I see, likes so much to give credit to others,
or more soars above the petty craving for self-celebrity.

If you come to any more conclusions about polymorphism, I should be very
glad to hear the result: it is delightful to have many points fermenting
in one's brain, and your letters and conclusions always give one plenty
of this same fermentation. I wish I could even make any return for all
your facts, views, and suggestions.

LETTER 23. TO J.D. HOOKER.

(23/1. The following extract gives the germ of what developed into an
interesting discussion in the "Origin" (Edition I., page 147). Darwin
wrote, "I suspect also that some cases of compensation which have been
advanced and likewise some other facts, may be merged under a more
general principle: namely, that natural selection is continually trying
to economise in every part of the organism." He speaks of the general
belief of botanis