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 8
... living long under not very close con- finement in their native country ! This is generally attributed to vitiated instincts ; but how many cultivated plants display the utmost vigour , and yet rarely or never seed ! In some few such ...
... living long under not very close con- finement in their native country ! This is generally attributed to vitiated instincts ; but how many cultivated plants display the utmost vigour , and yet rarely or never seed ! In some few such ...
Página 86
... living and leaving descendants . Its descend- ants would probably inherit a tendency to a similar slight deviation of structure . The tubes of the corollas of the common red and incarnate clovers ( Trifolium pratense and incarnatum ) do ...
... living and leaving descendants . Its descend- ants would probably inherit a tendency to a similar slight deviation of structure . The tubes of the corollas of the common red and incarnate clovers ( Trifolium pratense and incarnatum ) do ...
Página 97
... living fossils ; they have endured to the present day , from having inhabited a confined area , and from having thus been exposed to less severe competition . To sum up the circumstances favourable and un- favourable to natural ...
... living fossils ; they have endured to the present day , from having inhabited a confined area , and from having thus been exposed to less severe competition . To sum up the circumstances favourable and un- favourable to natural ...
Página 103
... living on the same piece of ground . And we well know that each species and each variety of grass is annually sowing almost countless seeds ; and thus , as it may be said , is striving its utmost to increase its numbers . Consequently ...
... living on the same piece of ground . And we well know that each species and each variety of grass is annually sowing almost countless seeds ; and thus , as it may be said , is striving its utmost to increase its numbers . Consequently ...
Página 113
... living , yet are often , in some degree , intermediate in character between existing groups ; and we can understand this fact , for the extinct species lived at very ancient epochs when the branching lines of descent had diverged less ...
... living , yet are often , in some degree , intermediate in character between existing groups ; and we can understand this fact , for the extinct species lived at very ancient epochs when the branching lines of descent had diverged less ...
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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