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
... follows from the high geo- metrical ratio of their increase , will be treated of . This is the doctrine of Malthus , applied to the whole animal and vegetable kingdoms . As many more individuals of each species are born than can ...
... follows from the high geo- metrical ratio of their increase , will be treated of . This is the doctrine of Malthus , applied to the whole animal and vegetable kingdoms . As many more individuals of each species are born than can ...
Página 29
... follow it as a trade : the sheep are placed on a table and are studied , like a picture by a connoisseur ; this is done three times at intervals of months , and the sheep are each time marked and classed , so that the very best may ...
... follow it as a trade : the sheep are placed on a table and are studied , like a picture by a connoisseur ; this is done three times at intervals of months , and the sheep are each time marked and classed , so that the very best may ...
Página 44
... follow . We must , however , in many cases , decide by a majority of naturalists , for few well- marked and well - known varieties can be named which have not been ranked as species by at least some com- petent judges . That varieties ...
... follow . We must , however , in many cases , decide by a majority of naturalists , for few well- marked and well - known varieties can be named which have not been ranked as species by at least some com- petent judges . That varieties ...
Página 51
... follow when another division is made , and when all the smallest genera , with from only one to four species , are absolutely excluded from the tables . These facts are of plain signification on the view that species are only strongly ...
... follow when another division is made , and when all the smallest genera , with from only one to four species , are absolutely excluded from the tables . These facts are of plain signification on the view that species are only strongly ...
Página 57
... follow from the struggle for life . ( Owing to this struggle for life , any variation , however slight , and from whatever cause proceeding , if it be in any degree profitable to an individual of any species , in its infinitely complex ...
... follow from the struggle for life . ( Owing to this struggle for life , any variation , however slight , and from whatever cause proceeding , if it be in any degree profitable to an individual of any species , in its infinitely complex ...
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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