The Origin of Species by Means of Natural Selection: Or, The Preservation of Favored Races in the Struggle for Life, Volumen2AMS Press, 1972 |
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Página 13
... species which can be crossed very rarely , or with extreme difficulty , but ... species . But the fertility of first crosses is likewise innately variable ; for ... allied species generally uniting with facility . But the correspondence ...
... species which can be crossed very rarely , or with extreme difficulty , but ... species . But the fertility of first crosses is likewise innately variable ; for ... allied species generally uniting with facility . But the correspondence ...
Página 82
... allied Species in the lowest known Fossiliferous Strata . There is another and allied difficulty , which is much more serious . I allude to the manner in which species belonging to several of the main divisions of the animal kingdom ...
... allied Species in the lowest known Fossiliferous Strata . There is another and allied difficulty , which is much more serious . I allude to the manner in which species belonging to several of the main divisions of the animal kingdom ...
Página 194
... allied or representative species occur , there will likewise be found some identical species ; and wherever many closely - allied species occur , there will be found many forms which some naturalists rank as distinct species , and ...
... allied or representative species occur , there will likewise be found some identical species ; and wherever many closely - allied species occur , there will be found many forms which some naturalists rank as distinct species , and ...
Contenido
CONTENTS OF VOL | 1 |
CHAPTER X | 48 |
CHAPTER XII | 129 |
Derechos de autor | |
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Términos y frases comunes
accumulated adapted admit adult affinity allied species ancient animals appear Archipelago arctic areas become beds believe birds breeds Cambrian changes characters classification climate closely allied continent crustaceans degree deposited difficulty distant distinct species domestic doubt embryo 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 seeds Silurian slight South America species belonging stage stamens sterility structure successive suppose terrestrial tertiary tion variations varieties whilst widely different wings