Introduction à la botanique structurelle et systématique, et physiologie végétale, : Étant un 5ème et refait du livre de texte botanique, illustré avec plus de treize cent boisés . r dischargede la cellule mère, quand, pendant quelques instants, ou d'habitude- i ^ i//ly pendant plusieurs heures, theyse comportent comme mfumory ani-mals, exécutant des spontaneousmoA-ements dans l'eau, jusqu'à ce qu'ils soient sur le ger-germer. Ce singulier mouvement Avas a détecté pour la première fois manyyyyyyyears il y a à Vaucheria FIG. 636. L'extrémité fruitiée d'une plante d'Aaucheria geminata (après Thuret); l'une des branches contenant encore sa spore. 637. Juste des spores en mouvement

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Introduction to structural and systematic botany, and vegetable physiology, : being a 5th and revedof the Botanical text-book, illustrated with over thirteen hundred woodcuts . r dischargefrom the parent cell, when, for some moments, or usual- i ^ I//ly for several hours, theybehave like mfusory ani-mals, executing spontaneousmoA-ements in the water, until they are about to ger-minate. This singular move-ment Avas first detected manyyears ago in Vaucheria FIG. 636. Fruiting end of a plant of Aaucheria geminata (after Thuret); one of thebranches still containing its spore. 637. Moving spore just escaped from the apex of theother branch ; the ciliary apparatus seen oyer the whole surface. 638. Spore in germination. FIG. 639-642. Successive steps in the germination of (Edogoniuin (Conferva) vesicata.643. The plant developed into a series of cells, four of which display the successive steps in theformation of a spore. 644. The locomotive spore with its vibratile cilia (copied from Thuret).AVhen the movement ceases, and it begins to germinate, it appears as in 639. (The antheridiaor fertilizing apparatus of these plants were not known when these figures were made.). SPONTANEOUS MOVEMENTS IN PLANTS. 349 (Fig. 89, G36). Immediately on its discharge from the motherplant the spore begins to move freely in the water, and continues todo so for some hours, when it fixes itself and begins to grow (Fig.638). Its movements, moreover, like those of the antheridial fila-ments or corpuscles, may be enfeebled or arrested by the applicationof a weak solution of opium or chloroform. Through these meansit has been ascertained that they are caused by the vibrations ofminute cilia which cover the surface, which are rendered visibleby thus enfeebling their movement, and which exhibit the closestresemblance to the vibratile cilia of animals, especially those of thepolygastric animalcules. In the Conferva tribe generally the vibra-tile cilia occupy one end of the spore, and are in some cases nu

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• bookauthorgra
• bookcentury1800
• bookdecade1860
• booksubjectbotany