Flowers, Fruits and LeavesMacmillan, 1886 - 147 páginas |
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Página 7
... less coloured , and which , like the calyx , is sometimes tubular , sometimes composed of separate leaves called petals ; thirdly , of one or more stamens , consisting of a stalk or filament , and a head or anther , in which the pollen ...
... less coloured , and which , like the calyx , is sometimes tubular , sometimes composed of separate leaves called petals ; thirdly , of one or more stamens , consisting of a stalk or filament , and a head or anther , in which the pollen ...
Página 8
... Pæony the pollen is carried by insects , and far less therefore is required ; yet even here the quantity produced is still large ; it has been estimated that each flower produces 1. ] PREVENTION OF SELF - FERTILISATION 9 between 3,000,000.
... Pæony the pollen is carried by insects , and far less therefore is required ; yet even here the quantity produced is still large ; it has been estimated that each flower produces 1. ] PREVENTION OF SELF - FERTILISATION 9 between 3,000,000.
Página 9
... less pollen ; according to Mr. Hassall about 240,000 grains to each flower ; while in Geum urbanum , according to Gærtner , only ten times more pollen is produced than is actually used in fertilisation . It might , however , be at first ...
... less pollen ; according to Mr. Hassall about 240,000 grains to each flower ; while in Geum urbanum , according to Gærtner , only ten times more pollen is produced than is actually used in fertilisation . It might , however , be at first ...
Página 10
... its access to the stigma . In these plants the pollen is less adherent , so that it can easily be blown away by the wind , which would be a disadvantage in most plants which are 1. ] INDUSTRY OF THE BEE . II fertilised by.
... its access to the stigma . In these plants the pollen is less adherent , so that it can easily be blown away by the wind , which would be a disadvantage in most plants which are 1. ] INDUSTRY OF THE BEE . II fertilised by.
Página 11
... less branched or hairy , which evidently must tend to increase their chances of catching the pollen . Moreover , as Mr. Darwin has observed , there does not appear to be a single instance of an irregular flower which is not fertilised ...
... less branched or hairy , which evidently must tend to increase their chances of catching the pollen . Moreover , as Mr. Darwin has observed , there does not appear to be a single instance of an irregular flower which is not fertilised ...
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Términos y frases comunes
Acacia advantage Agrimony allied animals anthers ants arrangement Beech bees belong branch canina capsule Cardamine carpel CHAP close colour common contrary corolla Crown 8vo curious Darwin Deadnettle dispersion distance Ditto Drosera Drosera rotundifolia edible Epilobium fertilised fertilised by insects flattened fleshy florets flower-head flowers Fritz Müller fruits genera genus Geranium Geranium dissectum Grant Allen ground grow Herb Herb Robert Hibiscus pedunculatus hirta honey hooks Hornbeam Horse Chestnut Illustrations inches insects instance internodes keel Lamium large number Lathyrus leaf-stalk leaflets leaves less light Lime lobed Maple maturity Moreover nearly observed ovary palmate perhaps petals pinnate pistil plants pods pollen Poplar produced protected resemblance ripe ripen scent Seedling seeds Senecio sepals small insects Spanish Chestnut species SQUIRTING CUCUMBER stalk stamens stamens and pistil stem stigma stomata surface Sycamore Thrincia throw trees tube upper Viola canina visited by insects wasp wind wings
Pasajes populares
Página 98 - But the leaves of the herbage at our feet take all kinds of strange shapes, as if to invite us to examine them. Starshaped, heart-shaped, spear-shaped, arrow-shaped, fretted, fringed, cleft, furrowed, serrated, sinuated; in whorls, in tufts, in spires, in wreaths endlessly expressive, deceptive, fantastic, never the same from footstalk to blossom ; they seem perpetually to tempt our watchfulness, and take delight in outstripping our wonder.
Página 117 - Here in the houseless wild, to direct the traveller's journey Over the sea-like, pathless, limitless waste of the desert.
Página 97 - Flowers seem intended for the solace of ordinary humanity : children love them ; quiet, tender, contented ordinary people love them as they grow; luxurious and disorderly people rejoice in them gathered : They are the cottager's treasure ; and in the crowded town, mark, as with a little...
Página 98 - Now. why is this marvellous variety, this inexhaustible treasury of beautiful forms ? Does it result from some innate tendency of each species? Is it intentionally designed to delight the eye of man ? Or has the form and size and texture some reference to the structure and organization, the habits and requirements, of the whole plant...
Página 3 - ... unknown until Mr. Darwin devoted himself to the subject. Our illustrious countryman was the first clearly to perceive that the essential service which insects perform to flowers, consists not only in transferring the pollen from the stamens to the pistil, but in transferring it from the stamens of one flower to the pistil of another. Sprengel had indeed observed in more than one instance that this was the case, but he did not altogether appreciate the importance of the fact. Mr. Darwin, however,...