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 4
... successive slight variations . I will then pass on to the variability of species in a state of nature ; but I shall , unfortunately , be compelled to treat this subject far too briefly , as it can be treated properly only by giving long ...
... successive slight variations . I will then pass on to the variability of species in a state of nature ; but I shall , unfortunately , be compelled to treat this subject far too briefly , as it can be treated properly only by giving long ...
Página 27
... successive generations . May not those natural- ists who , knowing far less of the laws of inheritance than does the breeder , and knowing no more than he does of the intermediate links in the long lines of descent , yet admit that many ...
... successive generations . May not those natural- ists who , knowing far less of the laws of inheritance than does the breeder , and knowing no more than he does of the intermediate links in the long lines of descent , yet admit that many ...
Página 28
... successive variations ; man adds them up in certain directions useful to him . In this sense he may be said to make for himself useful breeds . In The great power of this principle of selection is not hypothetical . It is certain that ...
... successive variations ; man adds them up in certain directions useful to him . In this sense he may be said to make for himself useful breeds . In The great power of this principle of selection is not hypothetical . It is certain that ...
Página 29
... successive generations , of differences absolutely in- appreciable by an uneducated eye - differences which I for one have vainly attempted to appreciate . Not one man in a thousand has accuracy of eye and judgment sufficient to become ...
... successive generations , of differences absolutely in- appreciable by an uneducated eye - differences which I for one have vainly attempted to appreciate . Not one man in a thousand has accuracy of eye and judgment sufficient to become ...
Página 79
... successive changes in the structure of their larvæ . So , conversely , modifications in the adult will probably often affect the structure of the larva ; but in all cases natural selection will ensure that modifica- tions consequent on ...
... successive changes in the structure of their larvæ . So , conversely , modifications in the adult will probably often affect the structure of the larva ; but in all cases natural selection will ensure that modifica- tions consequent on ...
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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