On the Origin of Species by Means of Natural Selection: Or The Preservation of Favored Races in the Struggle for Life, Volumen2D. Appleton, 1888 - 458 páginas |
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Página 9
... living . " Hair- less dogs have imperfect teeth : long - haired and coarse - haired animals are apt to have , as is asserted , long or many horns ; pigeons with feathered feet have skin between their outer toes ; pigeons with short ...
... living . " Hair- less dogs have imperfect teeth : long - haired and coarse - haired animals are apt to have , as is asserted , long or many horns ; pigeons with feathered feet have skin between their outer toes ; pigeons with short ...
Página 38
... living ou different plants , have been observed by Mr. Walsh to present in their larval or mature state , or in both states , slight , though constant differences in colour , size , or in the nature of their secretions . In some ...
... living ou different plants , have been observed by Mr. Walsh to present in their larval or mature state , or in both states , slight , though constant differences in colour , size , or in the nature of their secretions . In some ...
Página 83
... . These anomalous forms may be called living fossils ; they have endured to the present day , from having inhabited a confined area , and from having been exposed to less varied CHAP . IV . 83 Results of Natural Selection .
... . These anomalous forms may be called living fossils ; they have endured to the present day , from having inhabited a confined area , and from having been exposed to less varied CHAP . IV . 83 Results of Natural Selection .
Página 88
... living on the same piece of ground . And we know that each species and each variety of grass is annually sowing almost countless seeds ; and is thus striving , as it may be said , to the utmost to increase in number . Consequently , in ...
... living on the same piece of ground . And we know that each species and each variety of grass is annually sowing almost countless seeds ; and is thus striving , as it may be said , to the utmost to increase in number . Consequently , in ...
Página 89
... living in the United States . By considering the nature of the plants or animals which have in any country struggled successfully with the indigenes , and have there become naturalised , we may gain some crude idea in what manner some ...
... living in the United States . By considering the nature of the plants or animals which have in any country struggled successfully with the indigenes , and have there become naturalised , we may gain some crude idea in what manner some ...
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Términos y frases comunes
adapted admit affinities allied species America analogous ancient appear Asa Gray beak become bees believe belonging birds breeds cause cells characters climate closely allied colour continued crossed crustaceans degree developed difficulty distinct species doubt effects eggs embryo existing extinct extremely facts favourable fertilised fertility flowers formation formerly forms fossil Fritz Müller genera genus geological geological period Glacial period gradations greater number habits Hence hybrids important individuals inhabitants inherited insects instance instincts intercrossing intermediate kind lamellæ larvæ less living male mammals manner Marsupials migration modified descendants natural selection naturalists nearly nest occasionally occur oceanic islands offspring organisation organs parent peculiar perfect pigeon pistil pollen present preserved principle probably produced quadrupeds ranked reciprocal crosses remarked reproductive resemblance rudimentary seeds sexual selection slight South America stamens sterility structure struggle successive supposed tend theory tion variability variations varieties vary whilst whole wings young