The Origin of Species by Means of Natural Selection,: Or the Preservation of Favoured Races in the Struggle for LifeJohn Murray, Albemarle Street., 1891 - 432 páginas |
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Página 16
... namely , that all are descended from the rock - pigeon ( Columba livia ) , including under this term several geographical races or sub - species , which differ from each other in the most trifling respects . As several of the reasons ...
... namely , that all are descended from the rock - pigeon ( Columba livia ) , including under this term several geographical races or sub - species , which differ from each other in the most trifling respects . As several of the reasons ...
Página 18
... namely , -the improbability of man having formerly made seven or eight supposed species of pigeons to breed freely under domestication ; -these supposed species being quite unknown in a wild state , and their not having become anywhere ...
... namely , -the improbability of man having formerly made seven or eight supposed species of pigeons to breed freely under domestication ; -these supposed species being quite unknown in a wild state , and their not having become anywhere ...
Página 20
... namely , that nearly all the breeders of the various domestic animals and the cultivators of plants , with whom I have conversed , or whose treatises I have read , are firmly convinced that the several breeds to which each has attended ...
... namely , that nearly all the breeders of the various domestic animals and the cultivators of plants , with whom I have conversed , or whose treatises I have read , are firmly convinced that the several breeds to which each has attended ...
Página 22
... namely , by comparing the di- versity of flowers in the different varieties of the same species in the flower - garden ; the diversity of leaves , pods , or tubers , or whatever part is valued , in the kitchen - garden , in comparison ...
... namely , by comparing the di- versity of flowers in the different varieties of the same species in the flower - garden ; the diversity of leaves , pods , or tubers , or whatever part is valued , in the kitchen - garden , in comparison ...
Página 27
... namely , that we know hardly anything about the origin or history of any of our domestic breeds . But , in fact , a breed , like a dialect of a language , can hardly be said to have a distinct origin . A man preserves and breeds from an ...
... namely , that we know hardly anything about the origin or history of any of our domestic breeds . But , in fact , a breed , like a dialect of a language , can hardly be said to have a distinct origin . A man preserves and breeds from an ...
Otras ediciones - Ver todas
Términos y frases comunes
accumulated adapted admit affinities allied species America analogous ancient appear beak become bees believe belonging birds breeds cause cells characters climate closely allied colour continued crossed crustaceans degree developed difficulty distinct species domestic animals doubt effects eggs embryo existing extinct extremely facts favourable female fertilised fertility flowers formation formerly forms fossil Fritz Müller genera genus geological geological period Glacial period gradations greater number habits Hence hybrids important increase 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 resemblance rudimentary seeds sexual selection Silurian slight South America stamens sterility structure successive supposed tend theory tion variability variations varieties vary whilst whole wings young