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 1
... occurred to me , in 1837 , that something might perhaps be made out on this question by patiently accumulating and reflecting on all sorts of facts which could possibly have any bearing on it . After five years ' work I allowed myself ...
... occurred to me , in 1837 , that something might perhaps be made out on this question by patiently accumulating and reflecting on all sorts of facts which could possibly have any bearing on it . After five years ' work I allowed myself ...
Página 14
... occur ; but natural selection , as will hereafter be explained , will determine how far the new characters thus arising shall be preserved . When we look to the hereditary varieties or races of our domestic animals and plants , and ...
... occur ; but natural selection , as will hereafter be explained , will determine how far the new characters thus arising shall be preserved . When we look to the hereditary varieties or races of our domestic animals and plants , and ...
Página 23
... occur together in any other species of the whole family . Now , in every one of the domestic breeds , taking thoroughly well - bred birds , all the above marks , even to the white edging of the outer tail - feathers , sometimes concur ...
... occur together in any other species of the whole family . Now , in every one of the domestic breeds , taking thoroughly well - bred birds , all the above marks , even to the white edging of the outer tail - feathers , sometimes concur ...
Página 44
... occur in deciding whether or not to rank one form as a variety of another , even when they are closely connected by intermediate links ; nor will the commonly - assumed hybrid nature of the intermediate links always remove the ...
... occur in deciding whether or not to rank one form as a variety of another , even when they are closely connected by intermediate links ; nor will the commonly - assumed hybrid nature of the intermediate links always remove the ...
Página 51
... occur in a group having many species , than in one having few . To test the truth of this anticipation I have arranged the plants of twelve countries , and the coleopterous insects of two districts , into two nearly equal masses , the ...
... occur in a group having many species , than in one having few . To test the truth of this anticipation I have arranged the plants of twelve countries , and the coleopterous insects of two districts , into two nearly equal masses , the ...
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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