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 77
... animals without the concurrence of two individuals . Of aquatic animals , there are many self - fertilising hermaphrodites ; but here the currents of water offer an obvious means for an occasional cross . As in the case of flowers , I ...
... animals without the concurrence of two individuals . Of aquatic animals , there are many self - fertilising hermaphrodites ; but here the currents of water offer an obvious means for an occasional cross . As in the case of flowers , I ...
Página 111
... animals , namely , the cave - rat ( Noetoma ) , two of which were captured by Professor Silliman at above half a mile distance from the mouth of the cave , and therefore not in the profoundest depths , the eyes were lustrous and of ...
... animals , namely , the cave - rat ( Noetoma ) , two of which were captured by Professor Silliman at above half a mile distance from the mouth of the cave , and therefore not in the profoundest depths , the eyes were lustrous and of ...
Página 113
... animals brought from different countries which are here perfectly healthy . We have reason to believe that species ... animals , several authentic instances could be adduced of species having largely extended , within historical times ...
... animals brought from different countries which are here perfectly healthy . We have reason to believe that species ... animals , several authentic instances could be adduced of species having largely extended , within historical times ...
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