The Origin of Species by Means of Natural Selection,: Or the Preservation of Favoured Races in the Struggle for LifeJohn Murray, Albemarle Street., 1891 - 432 páginas |
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Página 2
... seeds that must be transported by certain birds , and which has flowers with separate sexes absolutely requiring the agency of certain insects to bring pollen from one flower to the other , it is equally preposterous to account for the ...
... seeds that must be transported by certain birds , and which has flowers with separate sexes absolutely requiring the agency of certain insects to bring pollen from one flower to the other , it is equally preposterous to account for the ...
Página 6
... seed - capsule . At long intervals of time , out of millions of individuals reared in the same country and fed on nearly the same food , deviations of structure so strongly pronounced as to deserve to be called monstrosities arise ; but ...
... seed - capsule . At long intervals of time , out of millions of individuals reared in the same country and fed on nearly the same food , deviations of structure so strongly pronounced as to deserve to be called monstrosities arise ; but ...
Página 7
... seed ! In some few cases it has been discovered that a very trifling change , such as a little more or less water at some particular period of growth , will determine whether or not a plant will produce seeds . I cannot here give the ...
... seed ! In some few cases it has been discovered that a very trifling change , such as a little more or less water at some particular period of growth , will determine whether or not a plant will produce seeds . I cannot here give the ...
Página 8
... seed . They occur rarely under nature , but are far from rare under culture . As a single bud out of the many thousands , produced year after year on the same tree under uniform conditions , has been known suddenly to assume a new ...
... seed . They occur rarely under nature , but are far from rare under culture . As a single bud out of the many thousands , produced year after year on the same tree under uniform conditions , has been known suddenly to assume a new ...
Página 20
... seeds of the same tree . Innumerable other examples could be given . The explanation , I think , is simple : from long - continued study they are strongly impressed with the differences between the several races ; and though they well ...
... seeds of the same tree . Innumerable other examples could be given . The explanation , I think , is simple : from long - continued study they are strongly impressed with the differences between the several races ; and though they well ...
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Términos y frases comunes
accumulated adapted admit affinities allied species America analogous ancient appear beak become bees believe belonging birds breeds cause cells characters climate closely allied colour continued crossed crustaceans degree developed difficulty distinct species domestic animals doubt effects eggs embryo existing extinct extremely facts favourable female fertilised fertility flowers formation formerly forms fossil Fritz Müller genera genus geological geological period Glacial period gradations greater number habits Hence hybrids important increase individuals inhabitants inherited insects instance instincts intercrossing intermediate kind lamellæ larvæ less living male mammals manner Marsupials migration modified descendants natural selection naturalists nearly nest occasionally occur oceanic islands offspring organisation organs parent peculiar perfect pigeon pistil pollen present preserved principle probably produced quadrupeds ranked reciprocal crosses remarked resemblance rudimentary seeds sexual selection Silurian slight South America stamens sterility structure successive supposed tend theory tion variability variations varieties vary whilst whole wings young