. The natural history of plants, their forms, growth, reproduction, and distribution;. Botany. 834 THE DISPERSION OF SPECIES BY MEANS OF FRUITS AND SEEDS. In one class of expulsive fruits the high degree of tension which finally results in the disruption and rolling up of particular tissues is caused by a swelling up of the cell-membranes or by the turgidity of the cells. One of the most curious instances is that of the Squirting Cucumber {Ecballium, Materium), which is shown in fig. 4581. This plant belongs to the Cucurbitacese and its fruit resembles a small fleshy cucumber beset with bristl
. The natural history of plants, their forms, growth, reproduction, and distribution;. Botany. 834 THE DISPERSION OF SPECIES BY MEANS OF FRUITS AND SEEDS. In one class of expulsive fruits the high degree of tension which finally results in the disruption and rolling up of particular tissues is caused by a swelling up of the cell-membranes or by the turgidity of the cells. One of the most curious instances is that of the Squirting Cucumber {Ecballium, Materium), which is shown in fig. 4581. This plant belongs to the Cucurbitacese and its fruit resembles a small fleshy cucumber beset with bristles and borne by a hooked stalk. The end of the stalk projects into the interior of the fruit like a stopper. When the seeds are quite .^ Kg. 468.—Sling-fruits. f**^^^*""^ • Ectallium Elaterium; branch bearing flowers and fruits. ' A fruit detached from its stalk and with its seeds squirting out. 8 Oxalis Aoetosella; entire plant with one unripe fruit on a hooked stalk, and one ripe fruit on an erect stalk ejecting its seeds; nat. size. * Vniipe trait ot Oxalis AcetoseUa; x6. '''Ri'gettmtoiOxalis Acetosella ejeatlngttieseedLs; x6. ripe the tissue surrounding them is transformed into a mucilaginous mass. Also the tissue in the neighbourhood of the conical stopper just referred to breaks down at the same time, and thus the connection between the stalk and the fruit is loosened. In the wall of the fruit there is a layer of cells which is under great tension, and endeavours to stretch itself out. As long as the fruit is unripe such expansion is prevented by the tense tissue close to the stalk, but with the ripening of the fruit this obstacle is removed. The fruit then severs itself from the conical end of the stalk and at the same moment the expansion of the strained layer of tissue takes place. The consequence is that the interior of the fruit is subjected to great pressure, and the seeds, together with the surrounding mucilage, are squirted out. Please note
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectbotany, bookyear1895
