RECORD: Darwin, C. R. & Francis Darwin. n.d. Dionaea. CUL-DAR59.1.30-32. Edited by John van Wyhe (Darwin Online, http://darwin-online.org.uk/)

REVISION HISTORY: Transcribed by Christine Chua and edited by John van Wyhe 10.2022. RN1

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).

Dionaea muscipula is the Venus flytrap. These notes are for Darwin, C. R. 1875. Insectivorous plants. London: John Murray. (F1217)


1

Dionæa

A, B & C are sections transversely across the midrib — [sketch] This being the shape of a complete section — [sketch] — The upper surface of each section the leaf can be recognized by the glands projecting from one margin of the section— B & C come from opposite laminæ— There are two or three rows of loose celled parenchyma in the middle of the lamina while ne nearer to both the upper & lower surface are smaller cells which have thicker la walls & contain chlorophyll

The direction of the long axis of all these cells both large and grea small is at right angles to the midrib— The proportion between the long & the short axes of the large loose cells is from varies between 3/1 & 5/1 — Some of the largest of these l loose cells are 1/50th inch in length— There is nothing much to be said about the smaller chlorophyll containing cells except that there are fewer rows of them on the upper surface of the leaf than on the lower— That is

[1v]

[sketches and fractions] Hk 5 tube out

2

the large loose cells are nearer the surface in of all to the upper or glandular side surface of the leaf than to the lower

farther to the midrib

D is a section perpendicular to A B & C — It shows that the large cells are nearly circular in transverse section — The collections of small dark rings coming at regular intervals are the bundles of vascular tissue seen in transverse section — These bundles of vascular consist of spiral & with I think annular vessels and of common vascular tissue — The spiral vessels are massed together & nearer the glandular or upper surface than the common vascular tissue is. Fig e shows a longitudinal section of a vascular bundle & made up of a bundle of spiral vessels & a bundle of ordinary vascular tissue lying side by side [text excised]

[32]

Dionæa

Figs A B C

[Fig] birds eye view of the back of the knife

[Fig] D is cut by a knife [illeg] vertically to the plane of the paper & parallel with stalk

[Fig] e 5 spiral a bundle of r


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

File last updated 3 November, 2022