RECORD: Darwin, C. R. Draft of Insectivorous plants, folio 50, 'Utricularia'. CC-OldLibraryGG.1.25. Edited by John van Wyhe (Darwin Online,

REVISION HISTORY: Transcribed by John van Wyhe and Kees Rookmaaker. Edited by John van Wyhe 7.2009. Corrections by Christine Chua. 11.2022 RN3

NOTE: See record in the Darwin Online manuscript catalogue, enter its Identifier here. Reproduced with the permission of Christ's College, Cambridge and William Huxley Darwin.

This single sheet is part of a draft of Insectivorous plants (p. 427), that was later used by Darwin's son George for mathematical exercises. The document was framed and displayed at Christ's College, Cambridge in 1909, see the catalogue, where it is still kept today. Compare with the similar manuscript fragment given by George Darwin to Dr Victor Albeck in Denmark in 1903 (SA-Haandskrift394A[.1]). Further sheets from the same draft can be found in CUL-DAR221. See other notes and papers on Darwin's book on insectivorous plants here.




(The vesicular bundles which run runs up the ventral surface of the bladder bifurcate at a little below distance from below to orifice; & each branch runs round the margin [side] of the orifice, as just from as beyond where the ends of the internal rim collar united with the basal margins of the valve. The two Lateral edges round on each side of the little valve project a little above the general surface of the bladder, & they [lateral margin abov] bear on the outside Hence long multicellular bristles like those on its antennae. Hence I suspect that the medial ventral surface part in of & the upper most sides lateral veins of a bladder the orifice & consists not only of a central infolded division of a leaf, but of two bifurcations bearing spines bristles, all coalesced together.)

(As to quadrifid & bifid processes, which line the whole inside interior of the bladder often one of the greatest


[mathematical notes by George Darwin, not transcribed]

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Citation: John van Wyhe, ed. 2002-. The Complete Work of Charles Darwin Online. (

File last updated 19 November, 2023