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
... 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 structure of this parasite , with its relations to several ...
... 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 structure of this parasite , with its relations to several ...
Página 8
... flowering of plants when transported from one climate to another . With animals the increased use or disuse of parts has had a more marked influence ; thus I find in the domestic duck that the bones of the wing weigh less and the bones ...
... flowering of plants when transported from one climate to another . With animals the increased use or disuse of parts has had a more marked influence ; thus I find in the domestic duck that the bones of the wing weigh less and the bones ...
Página 21
... flower - garden races of plants , most useful to man at different seasons and for different purposes , or so beautiful in his eyes , we must , I think , look further than to mere variability . We cannot suppose that all the breeds were ...
... flower - garden races of plants , most useful to man at different seasons and for different purposes , or so beautiful in his eyes , we must , I think , look further than to mere variability . We cannot suppose that all the breeds were ...
Página 22
... flowers of the present day are compared with drawings made only twenty or thirty years ago . When a race of plants ... flowers in the different varieties of the same species in the flower - garden ; the diversity of leaves , pods , or ...
... flowers of the present day are compared with drawings made only twenty or thirty years ago . When a race of plants ... flowers in the different varieties of the same species in the flower - garden ; the diversity of leaves , pods , or ...
Página 23
... flowers ; how unlike the flowers of the heartsease are , and how alike the leaves ; how much the fruit of the different kinds of gooseberries differ in size , colour , shape , and hairiness , and yet the flowers present very slight ...
... flowers ; how unlike the flowers of the heartsease are , and how alike the leaves ; how much the fruit of the different kinds of gooseberries differ in size , colour , shape , and hairiness , and yet the flowers present very slight ...
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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