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Circumnutation

Circumnutation is the revolving or swaying movement of growing plant organs. Darwin treated it as general among seedlings, with a role in how radicles enter the ground1. Bose described it as a lateral movement that arises during growth because most organs are not perfectly radial4. It matters because Darwin proposed that directed movements such as heliotropism are built from it6.

Earliest held
1880, Darwin, C.
Most discussed in
The Power of Movement in Plants, 1880
In the library
409 passages in 3 works
Rewritten
2026-10-03
18501875190019251950197520002025Darwin, C., 18801Darwin, C., 18802Darwin, C., 18803Bose, J. C., 19064Bose, J. C., 19065Bose, J. C., 19066Bose, J. C., 19067Bose, J. C., 19068
01

Darwin's survey of seedlings

Darwin's The Power of Movement in Plants (1880) opens its general considerations on seedlings with the generality of the circumnutating movement1. The same list names radicles, whose circumnutation Darwin calls of service, and the manner in which they penetrate the ground1. The held passage is a chapter summary. It names topics and gives no measurements, so it does not show how the movement was recorded or how large it was in any one organ.

02

Climbers and tendrils

Darwin also compared plants of different habit. Young climbing plants circumnutate in the ordinary manner. Once the stem reaches a height that differs between species, it elongates rapidly and the amplitude of the movement is immensely increased, evidently to favour the stem catching hold of a support2. Darwin added that tendrils made of modified leaves sweep wide circles, while ordinary leaves usually circumnutate nearly in the same vertical plane3. On this account the movement differs in size and shape between organs.

03

Bose on growth movements

Bose (1906) gave an account tied to growth. In bilateral organs these movements go to and fro in a fixed plane, in parallel with the to and fro movement of the leaflet of Biophytum4. Where the bilateral axis revolves, he wrote, the movement is as a rule circular or elliptical5. He held growing radial organs to be the ideally simple case, since the axis does not shift5.

04

Modified circumnutation tested

Bose also reported Darwin's theory that heliotropic movement is modified circumnutation. On that view the existing movement is increased in one direction and lessened or stopped in others6. He wrote that such a specimen was so hard to obtain that Darwin, though he noted the point, could not apply the test8. In the held passages the question is left open.

SourcesEach quotation was checked word for word against the passage it opens.
  1. Generality of the circumnutating movement—Radicles, their cir- cumnutation of service—Manner in which they penetrate the groundDarwin, C., 1880 · The Power of Movement in Plants · open at passage 1
  2. Again, climbing plants whilst young cireumnutate in the ordinary manner, but as soon as the stem has grown to a certain height, which is different for different species, it elongates rapidlyDarwin, C., 1880 · The Power of Movement in Plants · open at passage 1101
  3. This is conspicuously the case with those tendiils which consist of modified leaves, as these sweep wide circles; whilst ordinary leaves usually circumnutate nearly in the same vertical plane.Darwin, C., 1880 · The Power of Movement in Plants · open at passage 1101
  4. In bilateral growing organs, these movements are to and fro, in strict parallelism to the to and fro movements of the leaflet of Biophytum.Bose, J. C., 1906 · Plant Response as a Means of Physiological Investigation · open at passage 973
  5. as a rule, owing to the revolution of the bilateral axis, the movement of the leaflet is circular or ellipticalBose, J. C., 1906 · Plant Response as a Means of Physiological Investigation · open at passage 973
  6. the already existing movement (of circumnutation) had only to be increased in some one direction, and lessened or stopped in others, in order to become heliotropic or ap-heliotropicBose, J. C., 1906 · Plant Response as a Means of Physiological Investigation · open at passage 1350
  7. in order to prove conclusively that heliotropic curvatures were caused by the modification of the pre-existing movements, it would be necessary to show that they did not take place in those organs from which circumnutation was absentBose, J. C., 1906 · Plant Response as a Means of Physiological Investigation · open at passage 1350
  8. The difficulty of obtaining such a specimen is, however, so great, that Darwin, although he noted the point, was unable to apply the test.Bose, J. C., 1906 · Plant Response as a Means of Physiological Investigation · open at passage 1350
Linked ideas
Tropismprecursor of / follows
Darwin, as reported by Bose, held that heliotropic movements are circumnutation modified in direction; Bose notes the crucial test could not be applied.
Bose ties circumnutation to growth in organs that are not perfectly radial, so the movement follows from how the organ grows.
Bose frames circumnutation as a rhythmic responsive movement, placing it within his wider study of plant response.
Darwin's account places the radicle's circumnutation and its sensitive tip together in the same chapter summary.
Darwin treats heliotropism, apheliotropism and apogeotropism as modified forms of circumnutation, converted one into another by steps.
Where it is discussedPassages matching circumnutation, circumnutating movement, circumnutate, nutation
1880The Power of Movement in Plants · Darwin, C.399
1906Plant Response as a Means of Physiological Investigation · Bose, J. C.9
1992On Growth and Form · Thompson, D. A. W.1