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 71
... insects which visited them , so as to favour in any degree the transportal of the pollen , would likewise be favoured . We might have taken the case of insects visiting flowers for the sake of collecting pollen instead of nectar ; and ...
... insects which visited them , so as to favour in any degree the transportal of the pollen , would likewise be favoured . We might have taken the case of insects visiting flowers for the sake of collecting pollen instead of nectar ; and ...
Página 391
... insects . Mr. Wallace has also detected one such case with birds , but we have none with the larger quadrupeds . The much greater frequency of imitation with insects than with other animals , is probably the consequence of their small ...
... insects . Mr. Wallace has also detected one such case with birds , but we have none with the larger quadrupeds . The much greater frequency of imitation with insects than with other animals , is probably the consequence of their small ...
Página 470
... insects homologous with branchiæ , 151 . rudimentary , in insects , 411 . Wolf crossed with dog , 216 . of Falkland Isles , 363 . Wollaston , Mr. , on varieties of insects , 35 . on fossil varieties of shells in Madeira , " 39 . 3 " on ...
... insects homologous with branchiæ , 151 . rudimentary , in insects , 411 . Wolf crossed with dog , 216 . of Falkland Isles , 363 . Wollaston , Mr. , on varieties of insects , 35 . on fossil varieties of shells in Madeira , " 39 . 3 " 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