WCP1694

[1]

Frith Hill, Godalming

March 1st 1886

A. W. Bennett Esq

Dear Sir

In "Nature" of June 27. 1872 there is a notice of Kerners paper on dispersion of seeds by wind, with your initials, and from other articles of yours I know you take an interest in the question. Can you oblige me by referring me to any late observations on the subject, or anything bearing on it. You refer to the disbelief of botanists in the efficiency of this mode of transplant on account of the absence of evidence. But evidence is hardly to be expected. The case is like that of the dredgings in the deep sea. [2] I do not remember that the "Challenger" dredged up a single fragment of the skeleton of a recent whale, although the whales must be dying & depositing their skeletons at the bottom every year,— but they found hundreds & thousands of the ear-bones of ancient whales. So in shallow water shore-deposits, globigerina are difficult to find being masked by the mass of other deposits, while in the mid-ocean they form the bulk of the ocean floor-covering. In like manner the ^minute seeds brought to the Alps from great distances might be less than one per square mile per annum, & therefore were not found by Kerner. But this amount if present would amply serve to stock an oceanic island. The true & only way to search for them [3] is on newly exposed earth-surfaces when they vegetate & become conspicuous. The reason I think their dispersal for enormous distances is certainty is, that volcanic dust is so carried. Now this has a greater sp.gr. than small seeds, & this is an essential feature in the problem. Do you know any one who has determine the sizes & sp.gr. of the particles of volcanic ash carried to [one word crossed out illegible] different distances? This would pretty nearly settle the question, for where volcanic ash or any terrestrial debris is carried, seeds of not ^much greater bulk and ^less sp. gr. are sure to be carried. Is Treiman’s[?] Journal of Botany for the last ten years likely to contain any information on this interesting question? If so [4] I will look through it next time I come to town. It is the small seeds, like those of Orchideae[sic], many Campanulas, [one word illegible] &c., and that I suppose to be carried these great distances ^{by continuous gales} not those with pappus. Hoping you will be able to refer me to some information.

Believe me | Yours faithfully | Alfred R. Wallace [signature]