work, which will last for years as the foundation for all future treatises
on Geographical Distribution.

P.S.--You have paid me the highest conceivable compliment, by what you say
of your work in relation to my chapters on distribution in the "Origin,"
and I heartily thank you for it.


LETTER 390. FROM A.R. WALLACE TO CHARLES DARWIN.
The Dell, Grays, Essex, June 7th, 1876.

Many thanks for your very kind letter. So few people will read my book at
all regularly, that a criticism from one who does so will be very welcome.
If, as I suppose, it is only to page 184 of Volume I. that you have read,
you cannot yet quite see my conclusions on the points you refer to (land
molluscs and Antarctic continent). My own conclusion fluctuated during the
progress of the book, and I have, I know, occasionally used expressions
(the relics of earlier ideas) which are not quite consistent with what I
say further on. I am positively against any Southern continent as uniting
South America with Australia or New Zealand, as you will see at Volume I.,
pages 398-403, and 459-66. My general conclusions as to distribution of
land mollusca are at Volume II., pages 522-9. (390/1. "Geographical
Distribution" II., pages 524, 525. Mr. Wallace points out that "hardly a
small island on the globe but has some land-shells peculiar to it"--and he
goes so far as to say that probably air-breathing mollusca have been
chiefly distributed by air- or water-carriage, rather than by voluntary
dispersal on the land.) When you have read these passages, and looked at
the general facts which lead to them, I shall be glad to hear if you still
differ from me.