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 49
... rock - pigeon ; if we possessed all the intermediate varieties which have ever existed , we should have an extremely close series between both and the rock- pigeon ; but we should have no varieties directly in-. CHAP . X. ] 49 GEOLOGICAL ...
... rock - pigeon ; if we possessed all the intermediate varieties which have ever existed , we should have an extremely close series between both and the rock- pigeon ; but we should have no varieties directly in-. CHAP . X. ] 49 GEOLOGICAL ...
Página 50
... rock- pigeon , C. livia , whether they had descended from this species or from some other allied form , such as C. cenas . So , with natural species , if we look to forms very distinct , for instance to the horse and tapir , we have no ...
... rock- pigeon , C. livia , whether they had descended from this species or from some other allied form , such as C. cenas . So , with natural species , if we look to forms very distinct , for instance to the horse and tapir , we have no ...
Página 52
... rocks , and mark the process of degra- dation . The tides in most cases reach the cliff's only for a short time ... rock . At last the base of the cliff is undermined , huge fragments fall down , and these , remaining fixed , have to be ...
... rocks , and mark the process of degra- dation . The tides in most cases reach the cliff's only for a short time ... rock . At last the base of the cliff is undermined , huge fragments fall down , and these , remaining fixed , have to be ...
Página 53
... sea - cliffs are everywhere formed by the intersection of various formations . This being the case , we are compelled to admit that the escarpments owe their origin in chief part to the rocks of which they. CHAP . X. ] 53 THE LAPSE OF TIME ...
... sea - cliffs are everywhere formed by the intersection of various formations . This being the case , we are compelled to admit that the escarpments owe their origin in chief part to the rocks of which they. CHAP . X. ] 53 THE LAPSE OF TIME ...
Página 54
... rocks of which they are com- posed having resisted subaerial denudation better than the surrounding surface ; this surface consequently has been gradually lowered , with the lines of harder rock left projecting . Nothing impresses the ...
... rocks of which they are com- posed having resisted subaerial denudation better than the surrounding surface ; this surface consequently has been gradually lowered , with the lines of harder rock left projecting . Nothing impresses the ...
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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