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 67
... amount of migration due to climatal and other changes ; and when we see a species first appearing in any formation , the probability is that it only then first immigrated into that area . It is well - known , for instance , that several ...
... amount of migration due to climatal and other changes ; and when we see a species first appearing in any formation , the probability is that it only then first immigrated into that area . It is well - known , for instance , that several ...
Página 70
... amount of modification during the deposition of any one geological formation , a section would not include all the fine intermediate gradations which must on our theory have existed , but abrupt , though perhaps slight , changes of form ...
... amount of modification during the deposition of any one geological formation , a section would not include all the fine intermediate gradations which must on our theory have existed , but abrupt , though perhaps slight , changes of form ...
Página 92
... amount of change , during long and equal periods of time , may , perhaps , be nearly the same ; but as the accumulation of enduring formations , rich in fossils , depends on great masses of sediment being deposited on subsiding areas ...
... amount of change , during long and equal periods of time , may , perhaps , be nearly the same ; but as the accumulation of enduring formations , rich in fossils , depends on great masses of sediment being deposited on subsiding areas ...
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