Darwinism: An Exposition of the Theory of Natural Selection, with Some of Its ApplicationsMacmillan and Company, 1889 - 494 páginas |
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Página 11
... breed any kind of animals year after year , consuming or giving away all the increase we do not wish to keep just as they come to hand , our plants or animals will continue much the same ; but if every year we carefully save the best ...
... breed any kind of animals year after year , consuming or giving away all the increase we do not wish to keep just as they come to hand , our plants or animals will continue much the same ; but if every year we carefully save the best ...
Página 12
... breed from , we shall soon find that an improvement will take place , and that the average quality of our stock will be raised . This is the way in which all our fine garden fruits and vegetables and flowers have been pro- duced , as ...
... breed from , we shall soon find that an improvement will take place , and that the average quality of our stock will be raised . This is the way in which all our fine garden fruits and vegetables and flowers have been pro- duced , as ...
Página 26
... breed , unmolested , till they die at the end of ten years , as they might do if turned loose into a good - sized island with ample vegetable and insect food , but no other competing or destructive birds or quadrupeds their numbers ...
... breed , unmolested , till they die at the end of ten years , as they might do if turned loose into a good - sized island with ample vegetable and insect food , but no other competing or destructive birds or quadrupeds their numbers ...
Página 27
... breed at such a rate , that in a few years the progeny of any one species would , if allowed to increase unchecked , alone monopolise the land ; but all alike are kept within bounds by various destructive agencies , so that , though the ...
... breed at such a rate , that in a few years the progeny of any one species would , if allowed to increase unchecked , alone monopolise the land ; but all alike are kept within bounds by various destructive agencies , so that , though the ...
Página 30
... breeding animals being very numerous , shows that it is usually the amount of destruction which an animal or plant is exposed to , not its rapid multiplication , that determines its numbers in any country . The passenger - pigeon ...
... breeding animals being very numerous , shows that it is usually the amount of destruction which an animal or plant is exposed to , not its rapid multiplication , that determines its numbers in any country . The passenger - pigeon ...
Outras edições - Ver tudo
Darwinism: An Exposition of the Theory of Natural Selection, with Some of ... Alfred Russel Wallace Visualização integral - 1890 |
Darwinism: An Exposition of the Theory of Natural Selection, with Some of ... Alfred Russel Wallace Visualização integral - 1890 |
Darwinism: An Exposition of the Theory of Natural Selection ..., Volumes 1-2 Alfred Russel Wallace Visualização integral - 1889 |
Palavras e frases frequentes
abundant adapted adduced allied species America amount animals and plants appears birds breed brilliant butterflies cause characters climate closely allied colours of animals common concealment conspicuous continued cross-fertilisation crossed curious Darwin dicotyledons distinct species domestic animals effects eggs enemies Eocene evidence extinct facts faculty favourable female fertile fertilised flowers genera genus geological groups habits hybrids important increase individuals infertility inhabit insects intercrossing kind larva larvæ less living male mammalia mammals markings marsupials mimicry Miocene mode modified moths natural selection naturalists nests occur offspring organs Origin of Species peculiar pigeons Pliocene pollen portion possess probably produced Professor protectively coloured pupa regions remarkable resemblance seeds self-fertilisation Silurian similar specimens spots sterility structure struggle for existence supposed tail theory tints tion toes trees tropical usually variability variation varied varieties vegetation warning colours whole wild wings Zealand