o other adjacent islets." See Baker's "Flora of
the Mauritius and the Seychelles." Mr. Wallace says that, judging from
the soundings, Round Island was connected with Mauritius, and that when
it was "first separated [it] would have been both much larger and much
nearer the main island.") which I owe to you. Was there ever such an
enigma? If, in the course of a week or two, you can find time to let me
hear what you think, I should very much like to hear: or we hope to be
at Erasmus' on March 4th for a week. Would there be any chance of your
coming to luncheon then? What a case it is. Palms, screw-pines, four
snakes--not one being in main island--lizards, insects, and not one
land bird. But, above everything, such a proportion of individual
monocotyledons! The conditions do not seem very different from the Tuff
Galapagos Island, but, as far as I remember, very few monocotyledons
there. Then, again, the island seems to have been elevated. I wonder
much whether it stands out in the line of any oceanic current, which
does not so forcibly strike the main island? But why, oh, why should so
many monocotyledons have come there? or why should they have survived
there more than on the main island, if once connected? So, again, I
cannot conceive that four snakes should have become extinct in Mauritius
and survived on Round Island. For a moment I thought that Mauritius
might be the newer island, but the enormous degradation which the outer
ring of rocks has undergone flatly contradicts this, and the marine
remains on the summit of Round Island indicate the island to be
comparatively new--unless, indeed, they are fossil and extinct marine
remains. Do tell me what you think. There never was such an enigma.
I rather lean to separate immigration, with, of course, subsequent
modification; some forms, of course, also coming from Mauritius.
Speaking of Mauritius reminds me that I was so much pleased the day
before yesterday by reading a review of a book on the geology of St.
Helena, by an officer who knew nothing of my hurried observations, but
confirms nearly all that I have said on the general structure of the
island, and on its marvellous denudation. The geology of that island was
like a novel.

LETTER 387. TO A. BLYTT. Down, March 28th, 1876.

(387/1. The following refers to Blytt's "Essay on the Immigration of the
Norwegian Flora during Alternating Rainy and Dry Periods," Christiania,
1876.)

I thank you sincerely for your kindn