I am disposed to regard the Western Australian flora as the latest in point of origin, and I hope to prove it by development, and by the absence of various types.  If Western Australia ever had an old flora, I am inclined to suppose that it has been destroyed by the invasion of Eastern types after the union with East Australia.  My idea is that these types worked round by the south, and altered rapidly as they proceeded westward, increasing in species.  Nor can I conceive the Western Island, when surrounded by sea, harbouring a flora like its present one.

I have been disposed to regard New Caledonia and the New Hebrides as the parent country of many New Zealand and Australian forms of vegetation, but we do not know enough of the vegetation of the former to warrant the conclusion; and after all it would be but a slight modification of your views.

I very much like your whole working of the problem of the isolation and connection of New Zealand and Australia inter se and with the countries north of them, and the whole treatment of that respecting north and south migration over the globe is admirable....—­Ever most truly yours,

J.D.  HOOKER.

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SIR J. HOOKER TO A.R.  WALLACE

Royal Gardens, Kew.  November 10, 1880.

Dear Mr. Wallace,—­I have been waiting to thank you for “Island Life” till I should have read it through as carefully as I am digesting the chapters I have finished; but I can delay no longer, if only to say that I heartily enjoy it, and believe that you have brushed away more cobwebs that have obscured the subject than any other, besides giving a vast deal that is new, and admirably setting forth what is old, so as to throw new light on the whole subject.  It is, in short, a first-rate book.  I am making notes for you, but hitherto have seen no defect of importance except in the matter of the Bahamas, whose flora is Floridan, not Cuban, in so far as we know it....—­Very truly yours,

JOS.  D. HOOKER.

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TO SIR W. THISELTON-DYER

Pen-y-bryn, St. Peter’s Road, Croydon.  January 7, 1881.

Dear Mr. Thiselton-Dyer,—­If I had had your lecture before me when writing the last chapters of my book I should certainly have quoted you in support of the view of the northern origin of the Southern flora by migration along existing continents.  On reading it again I am surprised to find how often you refer to this; but when I read it on its first appearance I did not pay special attention to this point except to note that your views agreed more closely with those I had advanced, derived from the distribution of animals, than those of any previous writer on botanical distribution.  When, at a much later period, on coming to the end of my work, I determined to give