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 39
... look at individual differences , though of small interest to the systematist , as of the highest importance for us , as being the first steps towards such slight varieties as are barely thought worth recording in works on natural ...
... look at individual differences , though of small interest to the systematist , as of the highest importance for us , as being the first steps towards such slight varieties as are barely thought worth recording in works on natural ...
Página 208
... Look at the many outlying islands round a continent , and see how many of their inhabitants can be raised only to the rank of doubtful species . So it is if we look to past times , and compare the species which have just passed away ...
... Look at the many outlying islands round a continent , and see how many of their inhabitants can be raised only to the rank of doubtful species . So it is if we look to past times , and compare the species which have just passed away ...
Página 328
... look to the waters , and we do not find the beaver or musk - rat , but the coypu and capybara , rodents of the South American type . Innumerable other instances could be given . If we look to the islands off the American shore , however ...
... look to the waters , and we do not find the beaver or musk - rat , but the coypu and capybara , rodents of the South American type . Innumerable other instances could be given . If we look to the islands off the American shore , however ...
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