The Origin of Species by Means of Natural Selection,: Or the Preservation of Favoured Races in the Struggle for LifeAppleton, 1898 - 432 páginas |
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Página 10
... eral aboriginal species would at first have freely bred together and have produced quite fertile hybrids . So again I have lately acquired decisive evidence that the crossed offspring from the Indian humped and common cattle are inter ...
... eral aboriginal species would at first have freely bred together and have produced quite fertile hybrids . So again I have lately acquired decisive evidence that the crossed offspring from the Indian humped and common cattle are inter ...
Página 39
... eral sterility of crossed species may safely be looked at , not as a special acquirement or endowment , but as in- cidental on changes of an unknown nature in their sex- ual elements . Hybrids and Mongrels compared , independently of ...
... eral sterility of crossed species may safely be looked at , not as a special acquirement or endowment , but as in- cidental on changes of an unknown nature in their sex- ual elements . Hybrids and Mongrels compared , independently of ...
Página 66
... eral reasons can be given why each should not commonly include a graduated series of links between the species which lived at its commencement and close ; but I cannot assign due proportional weight to the following considerations ...
... eral reasons can be given why each should not commonly include a graduated series of links between the species which lived at its commencement and close ; but I cannot assign due proportional weight to the following considerations ...
Página 67
... eral stages of the same formation throughout Europe been correlated with perfect accuracy . We may safely infer that with marine animals of all kinds there has been a large amount of migration due to climatal and other changes ; and ...
... eral stages of the same formation throughout Europe been correlated with perfect accuracy . We may safely infer that with marine animals of all kinds there has been a large amount of migration due to climatal and other changes ; and ...
Página 114
... eral resemblance of the organic remains from the sev- eral stages of the Chalk formation , though the species are distinct in each stage . This fact alone , from its generality , seems to have shaken Professor Pictet in his belief in ...
... eral resemblance of the organic remains from the sev- eral stages of the Chalk formation , though the species are distinct in each stage . This fact alone , from its generality , seems to have shaken Professor Pictet in his belief in ...
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Términos y frases comunes
admit affinity allied species ancient animals appear Archipelago arctic areas become believe birds Cambrian changes characters cies classification climate closely allied common progenitor 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 individuals 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 parent parent-form peculiar perfect pistil plants pollen present probably produced quadrupeds reciprocal crosses regions remains remarked reproductive resemblance rocks rudimentary organs sediment seeds Silurian South America stage stamens sterility structure successive suppose terrestrial tertiary theory tion variations varieties whilst widely different wings