The Complete Work of Charles Darwin Online

RECORD: Darwin, C. R. 1874.07.11. Pinguicula / P grandiflorus / There are glands like in P vulgaris. CUL-DAR59.1.105. Edited by John van Wyhe (Darwin Online, http://darwin-online.org.uk/)

REVISION HISTORY: Transcribed by Christine Chua and edited by John van Wyhe 11.2021. RN2

NOTE: See record in the Darwin Online manuscript catalogue, enter its Identifier here. Reproduced with permission of the Syndics of Cambridge University Library and William Huxley Darwin. The volumes CUL-DAR 54-61 contain material for Darwin's book Insectivorous plants (1875).

Pinguicula is a genus of carnivorous plants known as butterworts. These notes are for Darwin, C. R. 1875. Insectivorous plants. London: John Murray. (F1217)

[105]

Pinguicula

July 11 74

P. Grandiflorus

There are glands like in P. vulgaris 3 celled [sketch] also the little nearly sersite glands: the distribution is the same as in P. vulgaris viz spreading all over the leaf at it upper parts, the 3 celled tentacles being replaced by long ones of 5 or 6 cells near the mid rib at the base of the leaf. The glands of these many celled tentacles have only 4-8 divisions whereas the 3 celled ones have nearly 30.

In the many celled tentacle: stalk: gland :: 25: 2 or 125:10 gland longitudinal rim

3 celled [do] stalk: gland :: 21:10

∴ The abortion of the glands on the long tentacle = 6 roughly (12 1/2 [÷] 2)

In Vulgaris Long glands stalk / gland = 35 length [÷] 2 longitudinal rim

Short – stalk/gland = 8 [illeg] [÷] 5 long eyes

∴ abortion = 175/16 = 10 roughly

Citation: John van Wyhe, ed. 2002-. The Complete Work of Charles Darwin Online. (http://darwin-online.org.uk/)