The Origin of Species by Means of Natural Selection: Or the Preservation of Favored Races in the Struggle for LifeD. Appleton, 1904 - 435 páginas |
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Página 18
... animals and plants , and compare them with closely allied species , we generally perceive in each domestic race , as already remarked , less uniformity of character than in true species . Domestic races often have a somewhat monstrous ...
... animals and plants , and compare them with closely allied species , we generally perceive in each domestic race , as already remarked , less uniformity of character than in true species . Domestic races often have a somewhat monstrous ...
Página 20
... animals and plants , it is not possible to come to any definite conclusion , whether they are descended from one or several wild species . The argument mainly relied on by those who believe in the multiple origin of our domestic animals ...
... animals and plants , it is not possible to come to any definite conclusion , whether they are descended from one or several wild species . The argument mainly relied on by those who believe in the multiple origin of our domestic animals ...
Página 21
... animals , kept by different tribes in different districts , might have varied and given . rise to distinct races . Since the discovery of flint tools in the superficial formations of many parts of the world , all geologists believe that ...
... animals , kept by different tribes in different districts , might have varied and given . rise to distinct races . Since the discovery of flint tools in the superficial formations of many parts of the world , all geologists believe that ...
Página 30
... animals being perfectly fertile . Some authors believe that long - continued domestication eliminates this strong tendency to sterility in species . From the history of the dog , and of some other domestic animals , this conclusion is ...
... animals being perfectly fertile . Some authors believe that long - continued domestication eliminates this strong tendency to sterility in species . From the history of the dog , and of some other domestic animals , this conclusion is ...
Página 35
... animals . Breeders habitually speak of an animal's organisation as some- thing plastic , which they can model almost as they please . If I had space I could quote numerous pas- sages to this effect from highly competent authorities ...
... animals . Breeders habitually speak of an animal's organisation as some- thing plastic , which they can model almost as they please . If I had space I could quote numerous pas- sages to this effect from highly competent authorities ...
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Términos y frases comunes
adapted affinities allied species America ancient appear Asa Gray beak become bees believe belonging birds breeds cause cells characters climate closely allied colour common continent crossed crustaceans degree developed difficulty distinct species domestic doubt effects eggs embryo existing extinct extremely facts favourable fertilised fertility flowers formation forms fossil Fritz Müller genera genus geological geological period Glacial period gradations greater number groups of species habits Hence hybrids important individuals inhabitants inherited insects instance instincts intercrossing intermediate kind lamellæ larvæ less living males mammals manner marsupials migration modified descendants natural selection naturalists nearly nest occasionally offspring organisation organs parent peculiar perfect pigeon pistil pollen present principle probably produced progenitor quadrupeds ranked remarked resemblance rudimentary seeds sexual selection Silurian slight South America stamens sterility structure successive supposed swimbladder tend theory tion trees variability variations varieties vary whilst whole wings young