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 2
... point is discussed in this volume on which facts cannot be adduced , often apparently leading to conclusions directly opposite to those at which I have arrived . A fair result can be obtained only by fully stating and balancing the ...
... point is discussed in this volume on which facts cannot be adduced , often apparently leading to conclusions directly opposite to those at which I have arrived . A fair result can be obtained only by fully stating and balancing the ...
Página 5
... points which strikes us is , that they generally differ more from each other than do the individuals of any one species or variety in a state of nature . And if we reflect on the vast diversity of the plants and animals which have been ...
... points which strikes us is , that they generally differ more from each other than do the individuals of any one species or variety in a state of nature . And if we reflect on the vast diversity of the plants and animals which have been ...
Página 9
... points of struc- ture and constitution in which the varieties and sub - varieties differ slightly from each other . The whole organisation seems to have become plastic , and departs in a slight degree from that of the parental type ...
... points of struc- ture and constitution in which the varieties and sub - varieties differ slightly from each other . The whole organisation seems to have become plastic , and departs in a slight degree from that of the parental type ...
Página 12
... point , if it could be cleared up , would be interesting ; if , for instance , it could be shown that the greyhound , bloodhound , terrier , spaniel , and bull - dog , which we all know propagate their kind truly , were the offspring of ...
... point , if it could be cleared up , would be interesting ; if , for instance , it could be shown that the greyhound , bloodhound , terrier , spaniel , and bull - dog , which we all know propagate their kind truly , were the offspring of ...
Página 16
... points of structure which are variable . The period at which the perfect plumage is acquired varies , as does the state of the down with which the nestling birds are clothed when hatched . The shape and size of the eggs vary . The ...
... points of structure which are variable . The period at which the perfect plumage is acquired varies , as does the state of the down with which the nestling birds are clothed when hatched . The shape and size of the eggs vary . The ...
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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