The Origin of Species by Means of Natural Selection: Or, The Preservation of Favored Races in the Struggle for Life, Volumen2D. Appleton, 1898 |
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Página 5
... allied hybrids , generally grow in the same garden , the visits of insects must be carefully prevented during the flowering season : hence hybrids , if left to themselves , will generally be fertilised during each generation by pollen ...
... allied hybrids , generally grow in the same garden , the visits of insects must be carefully prevented during the flowering season : hence hybrids , if left to themselves , will generally be fertilised during each generation by pollen ...
Página 13
... allied species generally uniting with facility . But the correspondence between syste- matic affinity and the facility of crossing is by no means strict . A multitude of cases could be given of very closely allied species which will not ...
... allied species generally uniting with facility . But the correspondence between syste- matic affinity and the facility of crossing is by no means strict . A multitude of cases could be given of very closely allied species which will not ...
Página 18
... allied species , and varieties of the same species , can usually , but not invariably , be grafted with ease . But this capacity , as in hybridisation , is by no means absolutely means absolutely governed by systematic affinity ...
... allied species , and varieties of the same species , can usually , but not invariably , be grafted with ease . But this capacity , as in hybridisation , is by no means absolutely means absolutely governed by systematic affinity ...
Página 23
... allied species , though the pollen - tubes protrude , they do not penetrate the stigmatic surface . Again , the male element may reach the female element but be incapable of causing an embryo to be developed , as seems to have been the ...
... allied species , though the pollen - tubes protrude , they do not penetrate the stigmatic surface . Again , the male element may reach the female element but be incapable of causing an embryo to be developed , as seems to have been the ...
Página 27
... allied , sterility is the common result , -in the one case from the conditions of life having been disturbed , in the other case from the organisation having been dis- turbed by two organisations being compounded into one . A similar ...
... allied , sterility is the common result , -in the one case from the conditions of life having been disturbed , in the other case from the organisation having been dis- turbed by two organisations being compounded into one . A similar ...
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Términos y frases comunes
admit affinity allied species ancient animals appear Archipelago arctic areas become believe belonging birds Cambrian changes characters cies classification climate closely allied continent crustaceans degree deposited difficulty distant distinct species domestic doubt embryo eral Europe existing extinct fact faunas fertilised fertility flowers formations formerly forms fossil fresh-water Fritz Müller Gärtner genera genus geological period geological record Glacial period groups of species habits hybrids hybrids produced important inhabitants inherited insects instance intermediate intervals land larvæ less living mammals manner marine Marsupials migration modified descendants mongrels mountains natural selection naturalists nearly occur oceanic islands offspring organisation palæontologists Palæozoic parent parent-form peculiar perfect pistil plants pollen present probably produced quadrupeds reciprocal crosses regions remains remarked reproductive resemblance rocks rudimentary organs seeds Silurian South America stage stamens sterility structure successive suppose terrestrial tertiary theory tion variations varieties whilst whole widely different wings