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 14
... point out what kind or what amount of difference , in any recognisable character , is sufficient to prevent two species crossing . It can be shown that plants most widely different in habit and general appearance , and having strongly ...
... point out what kind or what amount of difference , in any recognisable character , is sufficient to prevent two species crossing . It can be shown that plants most widely different in habit and general appearance , and having strongly ...
Página 25
... points of similarity . In both cases the sterility is inde- pendent of general health , and is often accompanied by excess of size or great luxuriance . In both cases the sterility occurs in various degrees ; in both , the male element ...
... points of similarity . In both cases the sterility is inde- pendent of general health , and is often accompanied by excess of size or great luxuriance . In both cases the sterility occurs in various degrees ; in both , the male element ...
Página 42
... point out between hybrid and mon- grel plants . On the other hand , the degrees and kinds of resemblance in mongrels and in hybrids to their respective parents , more especially in hybrids pro- duced from nearly related species , follow ...
... point out between hybrid and mon- grel plants . On the other hand , the degrees and kinds of resemblance in mongrels and in hybrids to their respective parents , more especially in hybrids pro- duced from nearly related species , follow ...
Página 50
... points of structure may have differed considerably from both , even perhaps more than they differ from each other . Hence , in all such cases , we should be unable to recognise the parent - form of any two or more spe- cies , even if we ...
... points of structure may have differed considerably from both , even perhaps more than they differ from each other . Hence , in all such cases , we should be unable to recognise the parent - form of any two or more spe- cies , even if we ...
Página 82
... point in Aus- tralia , and then to discuss the number and range of its productions . On the sudden Appearance of Groups of allied Species in the lowest known Fossiliferous Strata . There is another and allied difficulty , which is much ...
... point in Aus- tralia , and then to discuss the number and range of its productions . On the sudden Appearance of Groups of allied Species in the lowest known Fossiliferous Strata . There is another and allied difficulty , which is much ...
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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