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 76
... separated sexes . When the sexes are separated , although the male and female flowers may be produced on the same tree , pollen must be regularly carried from flower to flower ; and this will give a better chance of pollen being ...
... separated sexes . When the sexes are separated , although the male and female flowers may be produced on the same tree , pollen must be regularly carried from flower to flower ; and this will give a better chance of pollen being ...
Página 327
... separated by a space of ten degrees of latitude , and are exposed to considerably different conditions ; yet they are incomparably more closely related to each other than they are to the productions of Australia or Africa under nearly ...
... separated by a space of ten degrees of latitude , and are exposed to considerably different conditions ; yet they are incomparably more closely related to each other than they are to the productions of Australia or Africa under nearly ...
Página 364
... separated from each other or from the main- land by shallow channels , are more likely to have been continuously united within a recent period than the islands separated by deeper channels , we can understand how it is that a relation ...
... separated from each other or from the main- land by shallow channels , are more likely to have been continuously united within a recent period than the islands separated by deeper channels , we can understand how it is that a relation ...
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