SIR J. HOOKER TO A.R. WALLACE
Royal Gardens, Kew. August 2, 1880.
My dear Wallace,—I think you have made an immense advance to our knowledge of the ways and means of distribution, and bridged many great gaps.[15] Your reasoning seems to me to be sound throughout, though I am not prepared to receive it in all its details.
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 [pg 033] 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.