To Daniel Oliver   6 January [1875]¹

My dear Prof. Oliver

You told me not to speak of troubling you, & by all that is good & bad I am taking you at your word.² The case stands thus with Gentisea: we find bladders of a quite peculiar structure on the narrow leaves of G. ornata & africana, but not on those of G. filiformis; whereas we find ordinary bladders (like those of U. montana) on the rhizomes of filiformis.³ Now it seems to me very desirable to ascertain whether the same sp. of Gentisea bears two kinds of bladders. Could you therefore spare rhizomes of G. ornata or of G. africana—or more leaves of filiformis? It w^d be an extraordinary fact if the same species produces two kinds of bladders, & yet I must think this probable, on the supposition that G. filiformis is closely allied to G. ornata & Africana; the latter two having very similar bladders on their leaves.—

Yours very sincerely | Ch. Darwin