On the Origin of Species by Means of Natural Selection, Or, The Preservation of Favoured Races in the Struggle for LifeAppleton, 1898 |
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Página 5
... believe that their fertility has been di- minished in nearly all these cases by an independent cause , namely , by too close interbreeding . I have made so many experiments and collected so many facts , show- ing on the one hand that an ...
... believe that their fertility has been di- minished in nearly all these cases by an independent cause , namely , by too close interbreeding . I have made so many experiments and collected so many facts , show- ing on the one hand that an ...
Página 6
... believe , be accounted for by too close interbreeding having been avoided . Now let us turn to the results arrived at by a third most experienced hybridiser , namely , the Hon . and Rev. W. Herbert . He is as emphatic in his conclusion ...
... believe , be accounted for by too close interbreeding having been avoided . Now let us turn to the results arrived at by a third most experienced hybridiser , namely , the Hon . and Rev. W. Herbert . He is as emphatic in his conclusion ...
Página 9
... believe that the hybrids from Cervulus vaginalis and Reevesii , and from Phasianus colchicus with P. torquatus , are perfectly fertile . M. Quatrefages states that the hybrids from two moths ( Bombyx cyn- thia and arrindia ) were proved ...
... believe that the hybrids from Cervulus vaginalis and Reevesii , and from Phasianus colchicus with P. torquatus , are perfectly fertile . M. Quatrefages states that the hybrids from two moths ( Bombyx cyn- thia and arrindia ) were proved ...
Página 19
... vegetative systems , so I believe that the still more complex laws governing the facility of first crosses are incidental on unknown differences in their reproductive systems CHAP . IX . ] OF FIRST CROSSES AND OF HYBRIDS . 19.
... vegetative systems , so I believe that the still more complex laws governing the facility of first crosses are incidental on unknown differences in their reproductive systems CHAP . IX . ] OF FIRST CROSSES AND OF HYBRIDS . 19.
Página 22
... believe that modifica- tions in their structure and fertility have been slowly accumulated by natural selection , from an advantage having been thus indirectly given to the community to which they belonged over other communities of the ...
... believe that modifica- tions in their structure and fertility have been slowly accumulated by natural selection , from an advantage having been thus indirectly given to the community to which they belonged over other communities of the ...
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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