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 214
... birds , which vary partly in dependence on the situations chosen , and on the nature and temperature of the country inhabited , but often from causes wholly unknown to us : Audubon has given several remarkable cases of differences in ...
... birds , which vary partly in dependence on the situations chosen , and on the nature and temperature of the country inhabited , but often from causes wholly unknown to us : Audubon has given several remarkable cases of differences in ...
Página 219
... birds ' nests . If the old bird profited by this occasional habit through being enabled to migrate earlier or through any other cause ; or if the young were made more vigorous by advantage being taken of the mistaken instinct of another ...
... birds ' nests . If the old bird profited by this occasional habit through being enabled to migrate earlier or through any other cause ; or if the young were made more vigorous by advantage being taken of the mistaken instinct of another ...
Página 360
... birds ; of these 21 ( or perhaps 23 ) are peculiar , whereas of the 11 marine birds only 2 are peculiar ; and it is obvious that marine birds could arrive at these islands much more easily and frequently than land - birds . Bermuda , on ...
... birds ; of these 21 ( or perhaps 23 ) are peculiar , whereas of the 11 marine birds only 2 are peculiar ; and it is obvious that marine birds could arrive at these islands much more easily and frequently than land - birds . Bermuda , on ...
Contenido
VARIATION UNDER NATURE | 30 |
STRUGGLE FOR EXISTENCE | 45 |
NATURAL SELECTION | 59 |
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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