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 9
... families of the same hybrid have been raised at the same time from different parents , so as to avoid the ill effects of close interbreeding . On the contrary , brothers and sisters have usually been crossed in each successive ...
... families of the same hybrid have been raised at the same time from different parents , so as to avoid the ill effects of close interbreeding . On the contrary , brothers and sisters have usually been crossed in each successive ...
Página 13
... families ; and on the other hand , by very closely 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 ...
... families ; and on the other hand , by very closely 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 ...
Página 18
... families ; and , on the other hand , closely 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 ...
... families ; and , on the other hand , closely 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 ...
Página 77
... families , have really started into life at once , the fact would be fatal to the theory of evolution through natural selection . For the development by this means of a group of forms , all of which are descended from some one ...
... families , have really started into life at once , the fact would be fatal to the theory of evolution through natural selection . For the development by this means of a group of forms , all of which are descended from some one ...
Página 81
... families of fish now have a con- fined range ; the teleostean fishes might formerly have had a similarly confined range , and after having been largely developed in some one sea , have spread widely . Nor have we any right to suppose ...
... families of fish now have a con- fined range ; the teleostean fishes might formerly have had a similarly confined range , and after having been largely developed in some one sea , have spread widely . Nor have we any right to suppose ...
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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