The Origin of Species by Means of Natural Selection,: Or the Preservation of Favoured Races in the Struggle for LifeJohn Murray, Albemarle Street., 1891 - 432 páginas |
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Página 62
... advantage , for the good of another species ; and though statements to this effect may be found in works of natural history , I cannot find one case which will bear investigation . A structure. 62 [ CHAP . IV . NATURAL SELECTION .
... advantage , for the good of another species ; and though statements to this effect may be found in works of natural history , I cannot find one case which will bear investigation . A structure. 62 [ CHAP . IV . NATURAL SELECTION .
Página 63
... advantage , the process of modification would be very slow , and there would be simultaneously the most rigorous selection of all the young birds within the egg , which had the most powerful and hardest beaks , for all with weak beaks ...
... advantage , the process of modification would be very slow , and there would be simultaneously the most rigorous selection of all the young birds within the egg , which had the most powerful and hardest beaks , for all with weak beaks ...
Página 65
... advantage over other males , in their weapons , means of defence , or charms , which they have transmitted to their male offspring alone . Yet , I would not wish to attribute all sexual differences to this agency : for we see in our ...
... advantage over other males , in their weapons , means of defence , or charms , which they have transmitted to their male offspring alone . Yet , I would not wish to attribute all sexual differences to this agency : for we see in our ...
Página 68
... the plant had been rendered so highly attractive to insects that pollen was regularly carried from flower to flower , another process might commence . No naturalist doubts the advantage. 68 ILLUSTRATIONS OF THE ACTION OF [ CHAP . IV .
... the plant had been rendered so highly attractive to insects that pollen was regularly carried from flower to flower , another process might commence . No naturalist doubts the advantage. 68 ILLUSTRATIONS OF THE ACTION OF [ CHAP . IV .
Página 69
... advantage of what has been called the " physiological division of labour ; " hence we may believe that it would be advantageous to a plant to produce stamens alone in one flower or on one whole plant , and pistils alone in another ...
... advantage of what has been called the " physiological division of labour ; " hence we may believe that it would be advantageous to a plant to produce stamens alone in one flower or on one whole plant , and pistils alone in another ...
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Términos y frases comunes
accumulated adapted admit affinities allied species America analogous ancient appear beak become bees believe belonging birds breeds cause cells characters climate closely allied colour continued crossed crustaceans degree developed difficulty distinct species domestic animals doubt effects eggs embryo existing extinct extremely facts favourable female fertilised fertility flowers formation formerly forms fossil Fritz Müller genera genus geological geological period Glacial period gradations greater number habits Hence hybrids 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 occur oceanic islands offspring organisation organs parent peculiar perfect pigeon pistil pollen present preserved principle probably produced quadrupeds ranked reciprocal crosses remarked resemblance rudimentary seeds sexual selection Silurian slight South America stamens sterility structure successive supposed tend theory tion variability variations varieties vary whilst whole wings young