Flowers, Fruits and LeavesMacmillan, 1886 - 147 páginas |
Dentro del libro
Resultados 1-5 de 22
Página 3
... fact . Mr. Darwin , however , has not only made it clear from theoretical considerations , but has also proved it , in a variety of cases , by actual experiment . More recently Fritz Müller has even shown that in some cases pollen , if ...
... fact . Mr. Darwin , however , has not only made it clear from theoretical considerations , but has also proved it , in a variety of cases , by actual experiment . More recently Fritz Müller has even shown that in some cases pollen , if ...
Página 5
... which they do in considerable numbers . The bladders in fact act on the principle of an eel - trap , having an orifice closed with a flap which permits . an easy entrance , but 6 FLOWERS FERTILISED BY INSECTS . [ CHAP . effectually.
... which they do in considerable numbers . The bladders in fact act on the principle of an eel - trap , having an orifice closed with a flap which permits . an easy entrance , but 6 FLOWERS FERTILISED BY INSECTS . [ CHAP . effectually.
Página 9
... fact in some species this does occur ; but as we have seen , it is a great advantage to a species that the flower should be fertilised by pollen from a different stock . How then is self - fertilisation prevented ? There are three ...
... fact in some species this does occur ; but as we have seen , it is a great advantage to a species that the flower should be fertilised by pollen from a different stock . How then is self - fertilisation prevented ? There are three ...
Página 11
... fact had not been proved by any conclusive experiments . I therefore tried the following . If you bring a bee to some honey , she feeds quietly , goes back to the hive , stores away her honey , and returns with or without companions for ...
... fact had not been proved by any conclusive experiments . I therefore tried the following . If you bring a bee to some honey , she feeds quietly , goes back to the hive , stores away her honey , and returns with or without companions for ...
Página 19
... fact the stigmas come to maturity first , and have lost the possibility of fer- tilisation before the pollen is ripe . The pollen must therefore be brought by insects , and this is effected by small flies , which enter the leaf , either ...
... fact the stigmas come to maturity first , and have lost the possibility of fer- tilisation before the pollen is ripe . The pollen must therefore be brought by insects , and this is effected by small flies , which enter the leaf , either ...
Otras ediciones - Ver todas
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,...