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 16
... believe that any ornithologist would in this case place the English carrier , the short - faced tumbler , the runt , the barb , pouter , and fantail in the same genus ; more especially as in each of these breeds several truly ...
... believe that any ornithologist would in this case place the English carrier , the short - faced tumbler , the runt , the barb , pouter , and fantail in the same genus ; more especially as in each of these breeds several truly ...
Página 18
... believe that long - continued domestication eliminates this strong tendency to 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 ...
... believe that long - continued domestication eliminates this strong tendency to 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 ...
Página 21
... believe that the fuller's teasel , with its hooks , which cannot be rivalled by any mechanical contrivance , is only a variety of the wild Dipsacus ; and this amount of change may have suddenly arisen in a seedling . So it has probably ...
... believe that the fuller's teasel , with its hooks , which cannot be rivalled by any mechanical contrivance , is only a variety of the wild Dipsacus ; and this amount of change may have suddenly arisen in a seedling . So it has probably ...
Página 22
... believe in the natural capacity and years of practice requisite to become even a skilful pigeon - fancier . The same principles are followed by horticulturists ; but the variations are here often more abrupt . No one supposes that our ...
... believe in the natural capacity and years of practice requisite to become even a skilful pigeon - fancier . The same principles are followed by horticulturists ; but the variations are here often more abrupt . No one supposes that our ...
Página 25
... , explains , as I believe , the well - known fact , that in a number of cases we cannot recognise , and therefore do not know , the wild parent - stocks of the plants which have. CHAP . I. ] 25 UNCONSCIOUS SELECTION .
... , explains , as I believe , the well - known fact , that in a number of cases we cannot recognise , and therefore do not know , the wild parent - stocks of the plants which have. CHAP . I. ] 25 UNCONSCIOUS SELECTION .
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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