El poder de moviment en les plantes
- Idioma:
- anglès
- Completesa:
- Obra completa
- Autoria:
- Escrita per l'autor
- Estat del text:
- Sense soroll d'escaneig detectat (mesura automàtica sobre tot el text, no revisada a mà)
- Extensió:
- ~200.000 paraules · 955 passatges
Cita aquesta obra
- APACharles Darwin. (n.d.). The Power of Movement in Plants [El poder de moviment en les plantes]. Digital reproduction: SigPhi. https://sigphiai.com/ca/works/charles-darwin/the-power-of-movement-in-plants
- MLACharles Darwin. The Power of Movement in Plants [El poder de moviment en les plantes]. Digital reproduction, SigPhi, https://sigphiai.com/ca/works/charles-darwin/the-power-of-movement-in-plants.
- ChicagoCharles Darwin. The Power of Movement in Plants [El poder de moviment en les plantes]. Digital reproduction, SigPhi. https://sigphiai.com/ca/works/charles-darwin/the-power-of-movement-in-plants.
Referència de l’edició reproduïda. SigPhi és la reproducció digital, no l’editor. S’hi inclouen l’any, l’editorial i el traductor quan consten; «n.d.» indica que no consta l’any. La responsabilitat d’un pròleg o d’una nota es determina segons el passatge citat.
De què tracta
L'estudi de com es mouen les plantes: la circumnutació, el gir constant de la punta que creix, i la resposta a la llum, a la gravetat i al contacte.
Context i història
Publicat el 1880, i escrit amb el seu fill Francis, que hi va fer bona part dels experiments; la portada ho declara i el catàleg no, de manera que convé dir-ho. És l'últim llibre gran de Darwin i el més experimental: hi tapen puntes d'arrel amb caputxes minúscules, hi projecten llum de costat, hi mesuren desviacions al llarg d'hores. Al final proposa que la punta de l'arrel actua com un centre que dirigeix el moviment de la resta, una idea que va quedar de banda un segle i que la fisiologia vegetal recent ha tornat a discutir.
Context editorial, no una font citable: a diferència dels passatges de l'obra, aquestes dades no es poden contrastar amb el corpus.
remained stationary for about an hour, and then probably growth occurred on the side opposite to that which caused the geotropic curvature. In the case previously described the basal part of the very short radicle from being turned vertically upwards, was at first very little affected by geotropism. Filaments were affixed in two other instances to rather longer radicles protruding obliquely from seeds which had been turned upside down; and in these cases the lines traced on the horizontal glasses were only slightly zigzag, and the movement was always in the same general direction, through the action of geotropism. All these observations are liable to several causes of error, but we believe, from what will hereafter be shown with respect to the movements of the radicles of other plants, that they may be largely trusted. Fig. 2. Brassica oleracea: circumnutating and geotropic movement of radicle, traced on horizontal glass during 46 hours. Hypocotyl.—The hypocotyl protrudes through the seed-coats as a rectangular projection, which grows rapidly into an arch like the letter U turned upside down; the cotyledons being still enclosed within the seed. In whatever position the seed may be embedded in the earth or otherwise fixed, both legs of the arch bend upwards through apogeotropism, and thus rise vertically above the ground. As soon as this has taken place, or even earlier, the inner or concave surface of the arch grows more quickly than the upper or convex surface; and this tends to separate the two legs and aids in drawing the cotyledons out of the buried seed-coats. By the growth of the whole arch the cotyledons are ultimately dragged from beneath the ground, even from a considerable depth; and now the hypocotyl quickly straightens itself by the increased growth of the concave side.…