On the Origin of Species by Means of Natural Selection: Or The Preservation of Favoured Races in the Struggle for LifeHumphrey Milford, Oxford University Press, 1923 - 454 páginas |
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Página 5
... widely and is very numerous , and why another allied species has a narrow range and is rare ? Yet these relations are of the highest importance , for they determine the present welfare , and , as I believe , the future success and ...
... widely and is very numerous , and why another allied species has a narrow range and is rare ? Yet these relations are of the highest importance , for they determine the present welfare , and , as I believe , the future success and ...
Página 15
... widely in determining what characters are of generic value ; all such valuations being at present empirical . Moreover , on the view of the origin of genera which I shall presently give , we have no right to expect often to meet with ...
... widely in determining what characters are of generic value ; all such valuations being at present empirical . Moreover , on the view of the origin of genera which I shall presently give , we have no right to expect often to meet with ...
Página 37
... widely , and will get recognised as something distinct and valuable , and will then probably first receive a provincial name . In semi- civilised countries , with little free communication , the spreading and knowledge of any new sub ...
... widely , and will get recognised as something distinct and valuable , and will then probably first receive a provincial name . In semi- civilised countries , with little free communication , the spreading and knowledge of any new sub ...
Página 47
... widely extended , he will in the end generally be enabled to make up his own mind which to call varieties and which species ; but he will succeed in this at the expense of admitting much variation , and the truth of this admission will ...
... widely extended , he will in the end generally be enabled to make up his own mind which to call varieties and which species ; but he will succeed in this at the expense of admitting much variation , and the truth of this admission will ...
Página 49
... widely diffused within their own country ( and this is a different consideration from wide range , and to a certain extent from commonness ) , E L often give rise to varieties sufficiently well marked to VARIATION UNDER NATURE 49.
... widely diffused within their own country ( and this is a different consideration from wide range , and to a certain extent from commonness ) , E L often give rise to varieties sufficiently well marked to VARIATION UNDER NATURE 49.
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Términos y frases comunes
accumulated adapted affinities allied species America amount analogous ancient appear Archipelago become bees believe birds breeds cause cells characters cirripedes climate closely allied colour common parent continuous crossed crustaceans degree difficulty distinct species divergence doubt embryo endemic Europe existing exterminated extinct extremely facts favourable fertility flowers formations forms fossil Gärtner genera genus geological geological period Glacial period gradations greater number groups of species habits Hence hermaphrodites hybrids hybrids produced important individuals inhabitants inherited insects instance instincts intercrossing land larvæ less living male mammals manner Marsupials migration modification modified descendants natural selection naturalists nearly nest oceanic islands offspring organisation perfect pigeons pistil plants pollen present principle probably produced progenitor ranked reciprocal crosses remarked resemble rock-pigeon rudimentary organs seeds sexual selection Silurian slight South America sterility structure struggle successive suppose swimbladder tend theory tion trees variability variation vary whole widely