On the Origin of Species by Means of Natural Selection: Or The Preservation of Favored Races in the Struggle for Life, Volumen2D. Appleton, 1888 - 458 páginas |
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Página 24
... continued selection of slight variations . either in the leaves , the flowers , or the fruit , will produce races dit- fering from each other chiefly in these characters . It may be objected that the principle of selection has been ...
... continued selection of slight variations . either in the leaves , the flowers , or the fruit , will produce races dit- fering from each other chiefly in these characters . It may be objected that the principle of selection has been ...
Página 25
... continued during centuries , would improve and modify any breed , in the same way as Bake- well , Collins , & c . , by this very same process , only carried on more methodically , did greatly modify , even during their lifetimes , the ...
... continued during centuries , would improve and modify any breed , in the same way as Bake- well , Collins , & c . , by this very same process , only carried on more methodically , did greatly modify , even during their lifetimes , the ...
Página 27
... continued selection up to a standard of perfection comparable with that acquired by the plants in countries anciently civilised . In regard to the domestic animals kept by uncivilised man , it should not be overlooked that they almost ...
... continued selection up to a standard of perfection comparable with that acquired by the plants in countries anciently civilised . In regard to the domestic animals kept by uncivilised man , it should not be overlooked that they almost ...
Página 28
... continued , partly unconscious and partly methodical , selection . Perhaps the parent- bird of all fantails had only fourteen tail - feathers somewhat expanded , like the present Java fantail , or like individuals of other and distinct ...
... continued , partly unconscious and partly methodical , selection . Perhaps the parent- bird of all fantails had only fourteen tail - feathers somewhat expanded , like the present Java fantail , or like individuals of other and distinct ...
Página 64
... continued under the same conditions of life and profited by similar means of subsistence and defence . No country can be named in which all the native inhabitants are now so perfectly adapted to each 54 CHAP . IV . Natural Selection ...
... continued under the same conditions of life and profited by similar means of subsistence and defence . No country can be named in which all the native inhabitants are now so perfectly adapted to each 54 CHAP . IV . Natural Selection ...
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Términos y frases comunes
adapted admit affinities allied species America analogous ancient appear Asa Gray beak become bees believe belonging birds breeds cause cells characters climate closely allied colour continued crossed crustaceans degree developed difficulty distinct species doubt effects eggs embryo existing extinct extremely facts favourable fertilised fertility flowers formation formerly forms fossil Fritz Müller genera genus geological geological period Glacial period gradations greater number habits Hence hybrids important 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 reproductive resemblance rudimentary seeds sexual selection slight South America stamens sterility structure struggle successive supposed tend theory tion variability variations varieties vary whilst whole wings young