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 62
... seed were never destroyed , and could be ensured to germinate in a fitting place . So that in all cases , the average number of any animal or plant depends only indirectly on the number of its eggs or seeds . In looking at Nature , it ...
... seed were never destroyed , and could be ensured to germinate in a fitting place . So that in all cases , the average number of any animal or plant depends only indirectly on the number of its eggs or seeds . In looking at Nature , it ...
Página 68
... seed . Many of our orchidaceous plants absolutely require the visits of moths to remove their pollen - masses and thus to fertilise them . I have , also , reason to believe that humble - bees are indispensable to the fertilisation of ...
... seed . Many of our orchidaceous plants absolutely require the visits of moths to remove their pollen - masses and thus to fertilise them . I have , also , reason to believe that humble - bees are indispensable to the fertilisation of ...
Página 69
... seeds by the thousand ; what war between insect and insect - between insects , snails , and other animals with birds and beasts of prey - all striving to increase , and all feeding on each other or on the trees or their seeds and ...
... seeds by the thousand ; what war between insect and insect - between insects , snails , and other animals with birds and beasts of prey - all striving to increase , and all feeding on each other or on the trees or their seeds and ...
Página 70
... seed be resown , some of the varieties which best suit the soil or climate , or are naturally the most fertile , will beat the others and so yield more seed , and consequently in a few years quite supplant the other varieties . To keep ...
... seed be resown , some of the varieties which best suit the soil or climate , or are naturally the most fertile , will beat the others and so yield more seed , and consequently in a few years quite supplant the other varieties . To keep ...
Página 71
... seeds no doubt stands in the closest re- lation to the land being already thickly clothed by other plants ; so that the seeds may be widely distributed and fall on unoccupied ground . In the water - beetle , the structure of its legs ...
... seeds no doubt stands in the closest re- lation to the land being already thickly clothed by other plants ; so that the seeds may be widely distributed and fall on unoccupied ground . In the water - beetle , the structure of its legs ...
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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