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 12
... allied species , we generally perceive in each domestic race , as already remarked , less uniformity of character than in true species . Domestic races often have a somewhat monstrous character ; by which I mean , that , although ...
... allied species , we generally perceive in each domestic race , as already remarked , less uniformity of character than in true species . Domestic races often have a somewhat monstrous character ; by which I mean , that , although ...
Página 16
... allied to the carrier , but , instead of a long beak , has a very short and broad one . The pouter has a much elongated body , wings , and legs ; and its enormously developed crop , which it glories in inflating , may well excite ...
... allied to the carrier , but , instead of a long beak , has a very short and broad one . The pouter has a much elongated body , wings , and legs ; and its enormously developed crop , which it glories in inflating , may well excite ...
Página 22
... allied species . Some effect may be attributed to the direct and definite action of the external conditions of life , and some to habit ; but he would be a bold man who would account by such agencies for the differences between a dray ...
... allied species . Some effect may be attributed to the direct and definite action of the external conditions of life , and some to habit ; but he would be a bold man who would account by such agencies for the differences between a dray ...
Página 23
... allied sub - breeds . And when a cross has been made , the closest selection is far more indispensable even than in ordinary cases . If selection consisted merely in sepa- rating some very distinct variety , and breeding from it , the ...
... allied sub - breeds . And when a cross has been made , the closest selection is far more indispensable even than in ordinary cases . If selection consisted merely in sepa- rating some very distinct variety , and breeding from it , the ...
Página 36
... allied dimorphic species inhabiting another part of the Malay archipelago . Thus also with ants , the several worker - castes are generally quite distinct ; but in some cases , as we shall hereafter see , the castes are connected ...
... allied dimorphic species inhabiting another part of the Malay archipelago . Thus also with ants , the several worker - castes are generally quite distinct ; but in some cases , as we shall hereafter see , the castes are connected ...
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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