against me;
which pleases me much, for it is plain that our good work is spreading
in France. He speaks of the _engouement_ about this book, "so full of
empty and presumptuous thoughts."

* * * * *

_Down, Bromley, Kent, S.E. January 29, 1865._

My dear Wallace,--I must ease my mind by saying how much I admire the
two papers you have sent me.

That on parrots[43] contained most new matter to me, and interested me
_extremely_; that in the _Geographical Journal_[44] strikes me as an
epitome of the whole theory of geographical distribution: the comparison
of Borneo and New Guinea, the relation of the volcanic outbursts and the
required subsidence, and the comparison of the supposed conversion of
the Atlantic into a great archipelago, seemed to me the three best hits.
They are both indeed excellent papers.--Believe me yours very sincerely,

CHARLES DARWIN.

Do try what hard work will do to banish painful thoughts.[45]

P.S.--During one of the later French voyages, a _wild_ pig was killed
and brought from the Aru Islands to Paris. Am I not right in inferring
that this must have been introduced and run wild? If you have a clear
opinion on this head, may I quote you?

* * * * *

_5 Westbourne Grove Terrace, W. January 31, [1865?]._

Dear Darwin,--Many thanks for your kind letter. I send you now a few
more papers. One on Man is not much in your line. The other three are
bird lists, but in the introductory remarks are a few facts of
distribution that may be of use to you, and as you have them already in
the _Zoological Proceedings_, you can cut these up if you want
"extracts."

I hope you do not very much want the Aru pig to be a domestic animal run
wild, because I have no doubt myself it was the species peculiar to the
New Guinea fauna (_Sus papuensis_, Less.), a very distinct form. I have
no doubt it is this species, though I did not get it myself there,
because I was told that on a small island near, called there Pulo babi
(Pig Island), was a race of pigs (different from and larger than those
of the large islands) which had originated from the wreck of a large
ship near a century ago. The productions of the Aru Islands closely
resemble those of New Guinea, more than half the species of birds being
identical, as well as about half of the few known mammals.

I am beginning to work at some semi-mechanical work, drawing up
catalogues of parts of my coll