nto, and confined to same spots since
a Tertiary period, being due to their slow crawling powers; and yet we
know that other shell-snails have stocked a whole country within a very
few years with the same breeding powers, and same crawling powers,
when the conditions have been favourable to the life of the introduced
species. Hypothetically I should rather look at the case as owing
to--but as my notions are not very simple or clear, and only
hypothetical, they are not worth inflicting on you.

I had vowed not to mention my everlasting Abstract (340/5. The "Origin
of Species" was abbreviated from the MS. of an unpublished book.) to you
again, for I am sure I have bothered you far more than enough about
it; but as you allude to its previous publication I may say that I
have chapters on Instinct and Hybridism to abstract, which may take
a fortnight each; and my materials for Palaeontology, Geographical
Distribution and Affinities being less worked up, I daresay each of
these will take me three weeks, so that I shall not have done at soonest
till April, and then my Abstract will in bulk make a small volume. I
never give more than one or two instances, and I pass over briefly
all difficulties, and yet I cannot make my Abstract shorter, to be
satisfactory, than I am now doing, and yet it will expand to small
volume.

LETTER 341. TO J.D. HOOKER. Down [November?] 27th [1858].

What you say about the Cape flora's direct relation to Australia is a
great trouble to me. Does not Abyssinia highland, (341/1. In a letter
to Darwin, December 21st (?), 1858, Sir J.D. Hooker wrote: "Highlands of
Abyssinia will not help you to connect the Cape and Australian temperate
floras: they want all the types common to both, and, worse than that,
India notably wants them. Proteaceae, Thymeleae, Haemodoraceae, Acacia,
Rutaceae, of closely allied genera (and in some cases species), are
jammed up in S.W. Australia, and C.B.S. [Cape of Good Hope]: add to this
the Epacrideae (which are mere (paragraph symbol) of Ericaceae) and the
absence or rarity of Rasaceae, etc., etc., and you have an amount [of]
similarity in the floras and dissimilarity to that of Abyssinia and
India in the same features that does demand an explanation in any
theoretical history of Southern vegetation."), and the mountains on
W. coast in some degree connect the extra-tropical floras of Cape and
Australia? To my mind the enormous importance of the Glacial period
rises daily st