Unpublished paper, 'On the leaf-arrangement of crowberry [Empetrum nigrum]' by Hubert Airy

Description

Airy finds that the crowberry habitually exhibits a peculiar mole of variation in the arrangement of the leaves on different parts of the same twig. Out of 50 crowberry twigs taken at random, only four (and these fragments) preserved the same arrangement throughout. In the remaining 46 the leaf-arrangement was found to undergo a progressive change in ascending from the base of the twig to the summit— a change from a simpler order to others more complex. In general the basal order was that denoted by the fraction 2/5; and this was found to pass most frequently into 2/7, which in turn was found to pass into 2/9, with or without an intermediate set of whorls of 4:2/9 generally passed into whorls of 5, sometimes into 2/11, which was the most complex arrangement that was met with in this plant.

Marked on front as 'Archives Nov 2/76'. Includes 52 pages of diagrams mapping out the leaf arrangement of crowberry, and an index of the diagrams.

Subject: Botany

Received 8 May 1876. Read 15 June 1876. Communicated by Charles Darwin.

Whilst the Royal Society declined to publish this paper in full, an abstract of the paper was published in volume 25 of the Proceedings of the Royal Society as 'On the leaf-arrangement of the crowberry (empetrum nigrum)'.

Reference number

AP/58/7

Earliest possible date

01 May 1876

Physical description

Ink and graphite pencil on paper

Page extent

75 pages

Format

Manuscript
Diagram