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Darwin Correspondence Project

From S. B. Herrick   12 February 1876

34 McCulloh St. Baltimore Md USA,

Feb 12th. 1876.

Charles Darwin, M.A. &c.

Dear Sir,

I have read with the most intense interest your volume, lately published, on Insectivorous Plants.1 The positive testimony is absolutely conclusive. But I want to ask you whether you have ever experimented upon these plants in order to determine whether they can sustain life, as other vegetation does, only upon inorganic matter. Whether, in fact, this wonderful power of assimilation is only supplementary to the ordinary powers of vegetation, or takes in any degree its place. “It appears, therefore”, you say on p 18. of the Appleton Edition, “that the roots serve only to imbibe water”.2 Is this because there is only water to imbibe, or because they lack the normal power of roots?

In very carefully examining portions of Dionæa leaf through the Microscope it seemed to me that the sessile glands must be morphologically stomata; by throwing the object a little out of focus they look exactly like the stomata on the back of the leaf, both belonging to the epidermal systems, it seemed not improbable that this might be so.3 Have you ever studied the development of the glands? Mirbels observations upon the gemmæ of Marchantia polymorpha, that whichever side happens to lie uppermost developes stomata and whichever undermost root hairs, seems to give some color to the supposition.4

Enclosed please find addressed envelope, if my questions are not too silly to deserve an answer, will you give me one in a few words; if they are, or you are too busy to spare the time pardon the intrusion, and the questions which are inspired by a real desire to know, not mere idle curiosity | Yours truly & respectfully. | Sophie B. Herrick.


Insectivorous plants US ed. was published in August 1875 from stereotypes of the English edition (Publishers’ Weekly, 14 August 1875, p. 291).
Insectivorous plants US ed. was published by D. Appleton & Co. CD also noted in the same sentence quoted by Herrick that the roots ‘would absorb nutritious matter if present in the soil’ (ibid., p. 18).
CD described the sessile glands in leaves of Dionaea muscipula (Venus fly trap) in Insectivorous plants, pp. 287–8, 295–6. In her essay review of Insectivorous plants, Herrick wrote that the appearance of the sessile glands under the microscope was strongly suggestive of their being modified stomata (Herrick 1877, p. 813).
In his monograph on the anatomy and physiology of Marchantia polymorpha (common liverwort; Mirbel 1835, p. 353), Charles François Brisseau de Mirbel had noted that when reproducing asexually by means of gemmation, bulbils developed stomata on their upward-facing side and roots on the side facing the ground.


Herrick, Sophie Bledsoe. 1877. Insectivorous plants. [Review of Insectivorous plants.] Scribner’s Monthly 13: 804–15.

Insectivorous plants. By Charles Darwin. London: John Murray. 1875.

Insectivorous plants US ed. By Charles Darwin. New York: D. Appleton & Co. 1875.

Mirbel, Charles François Brisseau de. 1835. Recherches anatomiques et physiologiques sur le Marchantia polymorpha, pour servir a l’histoire du tissu cellulaire, de l’épiderme et des stomates. Mémoires de l’Académie des sciences de l’Institut de France 13: 337–436.


Inquires whether insectivorous habit in plants supplements or replaces the normal method of plant nutrition.

Letter details

Letter no.
Sophie McIlvaine Bledsoe (Sophie) (Bledsoe) Herrick
Charles Robert Darwin
Sent from
Source of text
DAR 166: 189
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 10390,” accessed on 4 December 2020,

Also published in The Correspondence of Charles Darwin, vol. 24