On the Origin of Species by Means of Natural Selection: Or, The Preservation of Favoured Races in the Struggle for LifeEaston Press, 1976 - 470 páginas |
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Página 64
... colour to each kind of grouse , and in keeping that colour , when once acquired , true and constant . Nor ought we to think that the occasional destruction of an animal of any particular colour would produce little effect : we should ...
... colour to each kind of grouse , and in keeping that colour , when once acquired , true and constant . Nor ought we to think that the occasional destruction of an animal of any particular colour would produce little effect : we should ...
Página 266
... coloured varieties of the same species yield fewer seeds , in the proportion of 86 to 100 , than the similarly coloured varieties . Yet these varieties differ in no respect except in the colour of their flowers ; and one variety can ...
... coloured varieties of the same species yield fewer seeds , in the proportion of 86 to 100 , than the similarly coloured varieties . Yet these varieties differ in no respect except in the colour of their flowers ; and one variety can ...
Página 467
... colour , 128 . " instinct of tumbling , 216 . young of , 406 . Pigs , black , not affected by the paint - root , 5 . modified by want of exercise , 163 . Pistil , rudimentary , 411 . Plants , poisonous , not affecting certain coloured ...
... colour , 128 . " instinct of tumbling , 216 . young of , 406 . Pigs , black , not affected by the paint - root , 5 . modified by want of exercise , 163 . Pistil , rudimentary , 411 . Plants , poisonous , not affecting certain coloured ...
Contenido
VARIATION UNDER NATURE | 30 |
STRUGGLE FOR EXISTENCE | 45 |
NATURAL SELECTION | 59 |
Derechos de autor | |
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Términos y frases comunes
accumulated adapted admit affinities allied species America ancient appear beak become bees believe belonging birds breeds cause cells characters climate closely allied colour common progenitor continuous crossed crustaceans degree developed difficulty distinct species divergence doubt effects eggs embryo existing exterminated extinct extremely facts favourable fertilised fertility flowers formation forms fossil Fritz Müller genera genus geological geological period gradations greater number groups of species habits Hence hybrids hybrids produced 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 offspring organisation organs Origin of Species parent peculiar perfect pigeons pistil plants pollen present preserved principle probably produced quadrupeds ranked reciprocal crosses remarked resemblance rudimentary seeds slight South America stamens sterility structure struggle successive supposed swimbladder theory variability variations varieties vary whilst whole wings young