and cross-fertilisation are important ends enough to lead to any modification, but can we suppose mere nourishment to be so important, seeing that it is so easily and almost universally obtained by extrusion of roots and leaves?  Here are plants which lose their roots and leaves to acquire the same results by infinitely complex modes!  What a wonderful and long-continued series of variations must have led up to the perfect “trap” in Utricularia, while at any stage of the process the same end might have been gained by a little more development of roots and leaves, as in 9,999 plants out of 10,000!

Is this an imaginary difficulty, or do you mean to deal with it in future editions of the “Origin"?—­Believe me yours very faithfully,

ALFRED R. WALLACE.

* * * * *

The Dell, Grays, Essex.  November 7, 1875.

Dear Darwin,—­Many thanks for your beautiful little volume on “Climbing Plants,” which forms a most interesting companion to your “Orchids” and “Insectivorous Plants.”  I am sorry to see that you have not this time given us the luxury of cut edges.

I am in the midst of printing and proof-sheets, which are wearisome in the extreme from the mass of names and statistics I have been obliged to introduce, and which will, I fear, make my book insufferably dull to all but zoological specialists.

My trust is in my pictures and maps to catch the public.

Hoping yourself and all your family are quite well, believe me yours very faithfully,

ALFRED R. WALLACE.

* * * * *

Down, Beckenham, Kent.  June 5, 1876.

My dear Wallace,—­I must have the pleasure of expressing to you my unbounded admiration of your book,[100] though I have read only to page 184—­my object having been to do as little as possible while resting.  I feel sure that you have laid a broad and safe foundation for all future work on Distribution.  How interesting it will be to see hereafter plants treated in strict relation to your views; and then all insects, pulmonate molluscs, and fresh-water fishes, in greater detail than I suppose you have given to these lower animals.  The point which has interested me most, but I do not say the most valuable point, is your protest against sinking imaginary continents in a quite reckless manner, as was started by Forbes, followed, alas, by Hooker, and caricatured by Wollaston and Murray.  By the way, the main impression which the latter author has left on my mind is his utter want of all scientific judgment.  I have lifted up my voice against the above view with no avail, but I have no doubt that you will succeed, owing to your new arguments and the coloured chart.  Of a special value, as it seems to me, is the conclusion that we must determine the areas chiefly by the nature of the mammals.  When I worked many years ago on this subject, I doubted much whether the now-called Palearctic