. British plants; their biology and ecology. Botany; Botany; Plant ecology. DEFENSIVE EQtnPMENT OF PLANTS 137 Dry fruits, like capsules, are not wortK eating. Other fruits escape destruction by concealing or disguising their presence. Protective mimicry is common among animals and insects, but it is only observed here and there in the vegetable world. Thus, some ripe fruits appear like dead twigs—, wallflower ; others are like small stones— , smooth and dull-coloured achenes. Sometimes, how- ever, mimicry may serve to attract attention. Thus, the achenes of the marigold resemble caterp
. British plants; their biology and ecology. Botany; Botany; Plant ecology. DEFENSIVE EQtnPMENT OF PLANTS 137 Dry fruits, like capsules, are not wortK eating. Other fruits escape destruction by concealing or disguising their presence. Protective mimicry is common among animals and insects, but it is only observed here and there in the vegetable world. Thus, some ripe fruits appear like dead twigs—, wallflower ; others are like small stones— , smooth and dull-coloured achenes. Sometimes, how- ever, mimicry may serve to attract attention. Thus, the achenes of the marigold resemble caterpillars. Birds pick them up and carry them some distance before they find out their mistake. (6) Seeds.—On p. 108 we pointed out that the seed was the xerophytic structure par excellence, with a wonderful tenacity of life, and with an extraordinary capacity for withstanding long periods of the most unfavourable con-. -a Fio. 47. — AcoEN WITH Fio. 48.—Ediblb Chestntit, with Three Habd Cupule (a). Nttts (a) in Spiny Ctrpui,E (6). ditions. This hardiness is brought aboiit by the with- drawal of water, so that the seed becomes partially desiccated, and the embryo is reduced to a state of sus- pended animation. Activity is only resumed when, on germiaation, water is absorbed and the cells become turgid. The xeroph3^ic characters of the seed are primarily a protection against natural perUs—drought, cold, etc.—^but the withdrawal of water renders them hard, and therefore impossible as food to swarms of living creatures. Dry structures are not subject to disease, since fungi and bacteria only flourish where moisture is abundant. Apart from this, however, seeds show special protective devices. Many are small and dull in colour, so that they cannot easily be distinguished from the soil particles among which they lie. It is another case of. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - co
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectbotany, bookyear1920
