On 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 13
... 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 given of very closely allied species which ...
... 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 given of very closely allied species which ...
Página 18
... 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 governed by systematic affinity . Although many ...
... 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 governed by systematic affinity . Although many ...
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 ...
Página 40
... closely allied species are more variable than those from very distinct species ; and this shows that the difference in the degree of variabil- ity graduates away . When mongrels and the more fertile hybrids are propagated for several ...
... closely allied species are more variable than those from very distinct species ; and this shows that the difference in the degree of variabil- ity graduates away . When mongrels and the more fertile hybrids are propagated for several ...
Página 41
... closely similar in all respects to the parent - form . Now hy- brids in the first generation are descended from spe ... allied to each other , are crossed with a third species , the hybrids are widely different from each other ; whereas ...
... closely similar in all respects to the parent - form . Now hy- brids in the first generation are descended from spe ... allied to each other , are crossed with a third species , the hybrids are widely different from each other ; whereas ...
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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