. The natural history of plants, their forms, growth, reproduction, and distribution;. Botany. CLIMBING PARASITES. GREEN-LEAVED PARASITES. TOOTHWORT. 173 not take place at either extremity, but always in the median part of the filament. It is so rapid that by the fifth day after the commencement of germination the entire seedling has increased fourfold in length. As early as the third day after the emergence of the tip that fastens itself in the earth, the integument of the seed, which until then continues to envelop the opposite extremity, is thrown off and the seedling's apex is exposed. The
. The natural history of plants, their forms, growth, reproduction, and distribution;. Botany. CLIMBING PARASITES. GREEN-LEAVED PARASITES. TOOTHWORT. 173 not take place at either extremity, but always in the median part of the filament. It is so rapid that by the fifth day after the commencement of germination the entire seedling has increased fourfold in length. As early as the third day after the emergence of the tip that fastens itself in the earth, the integument of the seed, which until then continues to envelop the opposite extremity, is thrown off and the seedling's apex is exposed. The reserve-food, given by the parent- plant to the seedling as provision for the journey, has meanwhile been absorbed and consumed, so that the seedling is now thrown entirely upon its own resources, and depends for sustenance upon the earth, to which it is firmly attached, and upon the surrounding air. Having no chlorophyll, it is not in a position to take up. -*£ x- MtH £â¢& '»».fi Tig. 34.âSeedlings of Parasitic Plants. ' te 7S i. z, 3, t, s, 6 The Great Dodder (Cuscuta Europcea). 'â a. a-1°. "⢠'2 A Broom-rape (Orobanche Epithymwri). w. 14, ie Wood Cow-wheat (Mela/mpyrwm gylvaticum). materials from the air; nor can it derive sufficient nutriment from the earth, even supposing that water is imbibed by the cells of the clavate extremity. There is no doubt that it now grows at the expense of the substances contained in the cells of this club-shaped end. The latter at once begins to shrivel and soon dies, whilst the upper part of the filament elongates conspicuously. Should this portion of the seedling meantime come into contact with a neighbouring plant, a rigid haulm, or anything else that will serve as a support, it straightway coils itself round the object in question, and its future is then, as a rule, assured. Failing such a support, the seedling, after the death of the clavate extremity, falls down and sinks to the ground. In doing so, it alm
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectbotany, bookyear1895
