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 34
... hybrid nature of the intermediate forms always remove the difficulty . In very many cases , however , one form is ranked as a variety of another , not because the inter- mediate links have actually been found , but because analogy leads ...
... hybrid nature of the intermediate forms always remove the difficulty . In very many cases , however , one form is ranked as a variety of another , not because the inter- mediate links have actually been found , but because analogy leads ...
Página 71
... anthers of one flower and then the stigma of another ; but it must not be supposed that bees would thus produce a multitude of hybrids between distinct i species ; for if a plant's own pollen and that. CHAP . IV . ] 71 OF INDIVIDUALS .
... anthers of one flower and then the stigma of another ; but it must not be supposed that bees would thus produce a multitude of hybrids between distinct i species ; for if a plant's own pollen and that. CHAP . IV . ] 71 OF INDIVIDUALS .
Página 121
... hybrid - zebra ; and Mr. W. C. Martin , in his excellent treatise on the horse , has given a figure of a similar mule . In four coloured drawings , which I have seen , of hybrids between the ass and zebra , the legs were much more ...
... hybrid - zebra ; and Mr. W. C. Martin , in his excellent treatise on the horse , has given a figure of a similar mule . In four coloured drawings , which I have seen , of hybrids between the ass and zebra , the legs were much more ...
Página 122
... hybrids resembling in their stripes , not their own parents , but other species of the genus . To admit this view is , as it seems to me , to reject a real for an unreal , or at least for an unknown , cause . It makes the works of God a ...
... hybrids resembling in their stripes , not their own parents , but other species of the genus . To admit this view is , as it seems to me , to reject a real for an unreal , or at least for an unknown , cause . It makes the works of God a ...
Página 219
... hybrids - Sterility various in degree , not universal , affected by close interbreeding , removed by domestication - Laws governing the sterility of hybrids - Sterility not a special endowment , but incidental on other differences , not ...
... hybrids - Sterility various in degree , not universal , affected by close interbreeding , removed by domestication - Laws governing the sterility of hybrids - Sterility not a special endowment , but incidental on other differences , not ...
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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