Insectivorous Plants
- Language:
- English
- Status:
- Complete work
- Authorship:
- Written by the author
- Condition of the text:
- No scanning noise detected (automatic measure over the whole text, not checked by hand)
- Extent:
- ~170,000 words · 792 passages
Cite this work
- APACharles Darwin. (n.d.). Insectivorous Plants. Digital reproduction: SigPhi. https://sigphiai.com/en/works/charles-darwin/insectivorous-plants
- MLACharles Darwin. Insectivorous Plants. Digital reproduction, SigPhi, https://sigphiai.com/en/works/charles-darwin/insectivorous-plants.
- ChicagoCharles Darwin. Insectivorous Plants. Digital reproduction, SigPhi. https://sigphiai.com/en/works/charles-darwin/insectivorous-plants.
Reference to the edition that SigPhi reproduces: SigPhi is its digital reproduction, not its publisher. The edition's year is not in the metadata (hence "n.d."), and the translator appears only when recorded.
What it is about
The 1875 book in which Darwin documented, experiment after experiment, that there are plants which capture animals, digest them and use their nitrogen.
Context and history
He did it with household means: drops of saliva, bits of meat, glass, hair, salts, all weighed in minute quantities, to see what the sundew responded to and what it did not. The finding that most surprised his contemporaries is that the plant discriminates: it responds to nitrogenous matter and not to an equivalent inert weight. The book matters for two reasons at once. It is a piece of his general argument — a carnivorous plant is an extreme adaptation and shows how far natural selection reaches — and it is also a model of how an investigation is done: everything is recorded, including the trials that yielded nothing. Darwin published more books on botany than on evolution, and this is among the best of them.
Editorial context, not a citable source: unlike the passages of the work itself, these statements cannot be checked against the corpus.
for the communication of a motor impulse to other parts of the leaf, as we may infer from the structure of the glands in some other genera of the Droseraceae. The extreme marginal tentacles differ slightly from the others. Their bases are broader, and besides their own vessels, they receive a fine branch from those which enter the tentacles on each side. Their glands are much elongated, and lie embedded on the upper surface of the pedicel, instead of standing at the apex. In other respects they do not differ essentially from the oval ones, and in one specimen I found every possible transition between the two states. In another specimen there were no long-headed glands. These marginal tentacles lose their irritability earlier than the others; and when a stimulus is applied to the centre of the leaf, they are excited into action after the others. When cut-off leaves are immersed in water, they alone often become inflected. The purple fluid or granular matter which fills the cells of the glands differs to a certain extent from that within the cells of the pedicels. For when a leaf is placed in hot water or in certain acids, the glands become quite white and opaque, whereas the cells of the pedicels are rendered of a bright red, with the exception of those close beneath the glands. These latter cells lose their pale red tint; and the green matter which they, as well as the basal cells, contain, becomes of a brighter green. The petioles bear many multicellular hairs, some of which near the blade are surmounted, according to Nitschke, by a few rounded cells, which appear to be rudimentary glands. Both surfaces of the leaf, the pedicels of the tentacles, especially the lower sides of the outer ones, and the petioles, are studded with minute papillae (hairs or trichomes), having a conical basis, and bearing on their summits two, and occasionally three or even four, rounded cells, containing much protoplasm.…