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Darwin Correspondence Project

From E. E. Klein   10 July 1874

The Brown Institution, | Wandsworth Road, S.W.

July 10. 1874.

Dear Mr. Darwin,

I have examined the specimens you have kindly sent me, and I find that although the specimen marked as “fibro-cartilage from artificial gastric juice” is undoubtedly very different from the specimens contained in the unlabelled leaves, still I have little doubt that the leaves have acted upon the fibro-cartilage.1 The specimen marked as “f.c. from art. g. j.”25 lines excised

In those specimens, that were contained in the unlabelled leaves, although only slightly altered, still there were distinct places, which have become altered in A similar manner, viz. more transparent, almost hyaline and the fibrillation of its bundles indistinct. I fancy the specimen contained in the leaf marked by a white thread (that on which some saliva had been placed) was most changed, next comes one that was smaller than the other two of the unlabelled leaves.

I will not omit to repeat, dear Sir, that it gives me the greatest pleasure if I can be of any service to you.

Believe me very sincerely | yours | E. Klein.

CD annotations

1.4 the specimen … j.” 1.5] ‘art G Ju’ added blue crayon
2.1 In those … leaves,] ‘In’ del pencil; ‘those’ altered to ‘Those’ pencil; ‘that … leaves,’ del pencil; ‘[In art dig in Gj] leaves of Drosera [6 words illeg]added pencil
2.3 almost hyaline and] ‘the fibrillation of its bundles indistinct.’ added ink


Klein had already examined the effect of Drosera (sundew) secretions on tooth and bone fragments (see letter from E. E. Klein, 14 May 1874).
CD cut out a section of the letter here; in Insectivorous plants, pp. 104–5, he quoted Klein’s remarks, which were probably from the excised portion of this letter. CD wrote: I therefore asked Dr. Klein to examine the specimens; and he reports that the two which had been subjected to artificial gastric juice were ‘in that state of digestion in which we find connective tissue when treated with an acid, viz. swollen, more or less hyaline, the fibrillar bundles having become homogeneous and lost their fibrillar structure.’


Reports results [partly excised] of examination of fibro-cartilage subjected to artificial gastric juice and to Drosera secretion. [See Insectivorous plants, pp. 104–5.]

Letter details

Letter no.
Edward Emanuel Klein
Charles Robert Darwin
Sent from
Brown Institution
Source of text
DAR 58.1: 77–8
Physical description
2pp inc †

Please cite as

Darwin Correspondence Project, “Letter no. 9542,” accessed on 24 February 2019,

Also published in The Correspondence of Charles Darwin, vol. 22