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 18
... admit that it is inci- dental on differences in the laws of growth of the two plants . We can sometimes see the reason why one tree will not take on another , from differences in their rate of growth , in the hardness of their wood , in ...
... admit that it is inci- dental on differences in the laws of growth of the two plants . We can sometimes see the reason why one tree will not take on another , from differences in their rate of growth , in the hardness of their wood , in ...
Página 34
... admit that this is the rule . But the sub- ject is surrounded by difficulties , for , looking to varie- ties produced under nature , if two forms hitherto re- puted to be varieties be found in any degree sterile to- gether , they are at ...
... admit that this is the rule . But the sub- ject is surrounded by difficulties , for , looking to varie- ties produced under nature , if two forms hitherto re- puted to be varieties be found in any degree sterile to- gether , they are at ...
Página 35
... admit- ting the directly opposite doctrine of Pallas , namely , that such conditions generally eliminate this tendency ; so that the domesticated descendants of species , which in their natural state probably would have been in some ...
... admit- ting the directly opposite doctrine of Pallas , namely , that such conditions generally eliminate this tendency ; so that the domesticated descendants of species , which in their natural state probably would have been in some ...
Página 40
... admits that hybrids from species which have long been cultivated are often variable in the first generation ; and I have myself seen striking instances of this fact . Gärtner further admits that hybrids between very closely allied ...
... admits that hybrids from species which have long been cultivated are often variable in the first generation ; and I have myself seen striking instances of this fact . Gärtner further admits that hybrids between very closely allied ...
Página 51
... Principles of Geology , which the future his- torian will recognise as having produced a revolution in natural science , and yet does not admit how vast have been the past periods of time , may at once. CHAP . X. ] 51 GEOLOGICAL RECORD .
... Principles of Geology , which the future his- torian will recognise as having produced a revolution in natural science , and yet does not admit how vast have been the past periods of time , may at once. CHAP . X. ] 51 GEOLOGICAL RECORD .
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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