Volume 1
Descriptive and illustrated catalogue of the physiological series of comparative anatomy contained in the museum of the Royal College of Surgeons in London.
- Royal College of Surgeons of England. Museum
- Date:
- 1833-1840
Licence: Public Domain Mark
Credit: Descriptive and illustrated catalogue of the physiological series of comparative anatomy contained in the museum of the Royal College of Surgeons in London. Source: Wellcome Collection.
Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.
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![described by Linnaeus in Amcenitates Academics, iv. p. 333, under the title Somnus Plantarumi] 29. A branch of Mimosa pudica, with two leaves; one of them is in the ex- panded state; the other contracted, but erect. [Although one only of the pinnules be touched, the contractile move- ment is quickly propagated along the other three: it consists of an approximation of the upper surfaces of the opposite subleaflets to each other, with an overlapping of those of the same side.] 30. A portion of a branch of Mimosa pudica, with the leaf bent down, in con- sequence of the action that takes place at the intumescent part of the joint. The leaf-stalks at the middle and lower part of the preparation appear to have been in the act of recovering their erect position when the branch was removed. The intumescence at the joints, in which the motive power resides, is well seen in this specimen. To see if the actions of plants were alFected by a continuation of stimulus similar to those of animals, I made the following experiments. As I took for granted that the analogy would go no further than the actions produced by external stimuli, my experiments were only such as had a tendency to these. For the purpose of making my experiments, I took three sensitive plants, having several others for any comparative experiments which might be thought necessary. I first pitched upon one leaf in each plant which was capable of the greatest motion of collapsing and erection; and behind each of these leaves a board was placed, on which was marked the greatest extent of the two motions; so that the leaf was like the index or radius of an arc. To have the greatest part of the day before me, I began my experi- ments at eight in the morning, while the leaves were in full expansion; and I continued them till four in the afternoon; as longer than this would not have been just, for they begin to collapse of themselves between five and six o'clock. [The leaves were stimulated to act five times during that period; and](https://iiif.wellcomecollection.org/image/b21470315_0001_0026.jp2/full/800%2C/0/default.jpg)
