On the Origin of Species by Means of Natural Selection: Or, The Preservation of Favoured Races in the Struggle for LifeEaston Press, 1976 - 470 páginas |
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Página 71
... flowers , also , which had their stamens and pistils placed , in relation to the size and habits of the particular insects which visited them , so as to favour in any degree the transportal of the pollen , would likewise be favoured ...
... flowers , also , which had their stamens and pistils placed , in relation to the size and habits of the particular insects which visited them , so as to favour in any degree the transportal of the pollen , would likewise be favoured ...
Página 76
... flowers on the same plant ; and the pollen of each flower readily gets on its own stigma without insect agency ; for ... flowers , it may be objected that pollen could seldom be carried from tree to tree , and at most only from flower to ...
... flowers on the same plant ; and the pollen of each flower readily gets on its own stigma without insect agency ; for ... flowers , it may be objected that pollen could seldom be carried from tree to tree , and at most only from flower to ...
Página 177
... flowers of two kinds , the one open of the ordinary structure , the other closed and imperfect . These two kinds of flowers sometimes differ wonderfully in structure , yet may be seen to graduate into each other on the same plant . The ...
... flowers of two kinds , the one open of the ordinary structure , the other closed and imperfect . These two kinds of flowers sometimes differ wonderfully in structure , yet may be seen to graduate into each other on the same plant . The ...
Contenido
VARIATION UNDER NATURE | 30 |
STRUGGLE FOR EXISTENCE | 45 |
NATURAL SELECTION | 59 |
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Términos y frases comunes
accumulated adapted admit affinities allied species America ancient appear beak become bees believe belonging birds breeds cause cells characters climate closely allied colour common progenitor continuous crossed crustaceans degree developed difficulty distinct species divergence doubt effects eggs embryo existing exterminated extinct extremely facts favourable fertilised fertility flowers formation forms fossil Fritz Müller genera genus geological geological period gradations greater number groups of species habits Hence hybrids hybrids produced important increase individuals inhabitants inherited insects instance instincts intercrossing intermediate kind lamellæ larvæ less living male mammals manner marsupials migration modified descendants natural selection naturalists nearly nest occasionally offspring organisation organs Origin of Species parent peculiar perfect pigeons pistil plants pollen present preserved principle probably produced quadrupeds ranked reciprocal crosses remarked resemblance rudimentary seeds slight South America stamens sterility structure struggle successive supposed swimbladder theory variability variations varieties vary whilst whole wings young