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 vii
... sterility of first crosses and of 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 ...
... sterility of first crosses and of 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 ...
Página xii
... sterility of hybrids , added to and corrected . Pyrgoma found in the chalk . Extinct forms serving to connect existing groups . On earth adhering to the feet of migratory birds . On the wide geographical range of a species of Galaxias ...
... sterility of hybrids , added to and corrected . Pyrgoma found in the chalk . Extinct forms serving to connect existing groups . On earth adhering to the feet of migratory birds . On the wide geographical range of a species of Galaxias ...
Página 18
... sterility in species . From the history of the dog , and of some other domestic animals , this conclusion is probably quite correct , if applied to species closely related to each other . But to extend it so far as to suppose that ...
... sterility in species . From the history of the dog , and of some other domestic animals , this conclusion is probably quite correct , if applied to species closely related to each other . But to extend it so far as to suppose that ...
Página 30
... sterility of hybrids ; but plants not propagated by seed are of little importance to us , for their endurance is only temporary . Over all these causes of Change , the accumulative action of Selection , whether applied methodically and ...
... sterility of hybrids ; but plants not propagated by seed are of little importance to us , for their endurance is only temporary . Over all these causes of Change , the accumulative action of Selection , whether applied methodically and ...
Página 219
... sterility of first crosses and of 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 ...
... sterility of first crosses and of 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 ...
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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