On the Origin of Species by Means of Natural Selection: Or The Preservation of Favored Races in the Struggle for Life, Volumen2D. Appleton, 1888 - 458 páginas |
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Página xv
... produced , chiefly by intercrossing , but likewise by variation , all our existing species . In 1826 Professor Grant , in the concluding paragraph in his well known paper ( Edinburgh Philosophical Journal , ' vol . xiv . p . 283 ) on ...
... produced , chiefly by intercrossing , but likewise by variation , all our existing species . In 1826 Professor Grant , in the concluding paragraph in his well known paper ( Edinburgh Philosophical Journal , ' vol . xiv . p . 283 ) on ...
Página xvii
... produced by the conditions of life are gradual . He argues with much force on general grounds that species are not immutable productions . But I cannot see how the two supposed " impulses " account in a scientific sense for the numerous ...
... produced by the conditions of life are gradual . He argues with much force on general grounds that species are not immutable productions . But I cannot see how the two supposed " impulses " account in a scientific sense for the numerous ...
Página 7
... produce seeds . I cannot here give the details which I have collected and elsewhere published on this curious subject ; but to show how singular the laws are which determine the repro- duction of animals under confinement , I may ...
... produce seeds . I cannot here give the details which I have collected and elsewhere published on this curious subject ; but to show how singular the laws are which determine the repro- duction of animals under confinement , I may ...
Página 8
... produced a single bud with a new and sometimes widely different character from that of the other buds on the same plant . These bud variations , as they may be named , can be pro- pagated by grafts , offsets , & c . , and sometimes by ...
... produced a single bud with a new and sometimes widely different character from that of the other buds on the same plant . These bud variations , as they may be named , can be pro- pagated by grafts , offsets , & c . , and sometimes by ...
Página 13
... produced under domestication ; I believe that a small part of the difference is due to their being descended from distinct species . In the case of strongly marked races of some other domesticated species , there is presumptive or even ...
... produced under domestication ; I believe that a small part of the difference is due to their being descended from distinct species . In the case of strongly marked races of some other domesticated species , there is presumptive or even ...
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Términos y frases comunes
adapted admit affinities allied species America analogous ancient appear Asa Gray beak become bees believe belonging birds breeds cause cells characters climate closely allied colour continued crossed crustaceans degree developed difficulty distinct species doubt effects eggs embryo existing extinct extremely facts favourable fertilised fertility flowers formation formerly forms fossil Fritz Müller genera genus geological geological period Glacial period gradations greater number habits Hence hybrids important 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 reproductive resemblance rudimentary seeds sexual selection slight South America stamens sterility structure struggle successive supposed tend theory tion variability variations varieties vary whilst whole wings young