My dear Darwin,

Those Helices ought to be ashamed of themselves for surviving in salt water; I s^d. have given them credit, I confess, for better behavour.² However, in the meantime I must congratulate you on the addition of another ♂ to your vivarium;³ &, although I sympathise with you in your disappointment, the result of this infamous experiment will compensate for the difference between a ♂ and ♀, I am sure.—

Those dishonest Mollusks were collected, in Porto Santo, during the 2^nd. week of May, 1855.⁴ It is possible, perhaps, that, like seasoned casks, which are proof against the vicissitudes of this nether world, they may become more tenacious of life in proportion to their age: so that if my thesis be true that some of them have lived since miocene times, the patriarchs whose opercula have become thickened into solid rock might survive for ten years (instead of days) in aquis valde diabolicis maritimis.—

I have no others, I think, except more of the Porto Santans; & those not in such good condition as the bag-full w^h. you took,—being chiefly (if not altogether) defunct.—

Of shell-less Mollusks, there are in Insulis Maderensibus a few slimy Limaces (all the same as European species), 2 Testacellæ (D^o.), & 3 Vitrinæ,—w^h. are supposed by Lowe (who however shaves things very finely) to be peculiar to those islands.⁵ They are however the exact “representatives” of the 3 European Vitrinæ; hence I, who am less morbidly sensitive about specific differences (though believing in “species” more & more every day),⁶ s^d. be inclined to regard them as mere insular modifications. The others we suppose have been introduced by man,—but if you choose to substitute “mare” instead of “homo”, I will not refuse my assent.— I am taking a week’s interlude, between the paroxisms of Madeira work, to revise a British genus of Coleopterous atoms,—the 25 species of w^h. might be put into the compass of a hollow pea.—

Vivat Darwinianus masculus sextus.—

Your’s very sincerely | T V Wollaston.