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 22
... common gooseberry may be quoted . We see an astonishing im- provement in many florists ' flowers , when the flowers of the present day are compared with drawings made only twenty or thirty years ago . When a race of plants is once ...
... common gooseberry may be quoted . We see an astonishing im- provement in many florists ' flowers , when the flowers of the present day are compared with drawings made only twenty or thirty years ago . When a race of plants is once ...
Página 27
... common goose has not given rise to any marked varieties ; hence the Toulouse and the common breed , which differ only in colour , that most fleeting of characters , have lately been exhibited as distinct at our poultry - shows . These ...
... common goose has not given rise to any marked varieties ; hence the Toulouse and the common breed , which differ only in colour , that most fleeting of characters , have lately been exhibited as distinct at our poultry - shows . These ...
Página 30
... common species , vary most - Species of the larger genera in each country vary more frequently than the species of the smaller genera -Many of the species of the larger genera resemble varieties in being very closely , but unequally ...
... common species , vary most - Species of the larger genera in each country vary more frequently than the species of the smaller genera -Many of the species of the larger genera resemble varieties in being very closely , but unequally ...
Página 33
... common fact that the female produces offspring of two sexes which sometimes differ from each other in a wonderful manner . Doubtful Species . The forms which possess in some considerable degree the character of species , but which are ...
... common fact that the female produces offspring of two sexes which sometimes differ from each other in a wonderful manner . Doubtful Species . The forms which possess in some considerable degree the character of species , but which are ...
Página 34
... common , but sometimes the one first described , as the species , and the other as the variety . But cases of great difficulty , which I will not here enumerate , sometimes arise in deciding whether or not to rank one form as a variety ...
... common , but sometimes the one first described , as the species , and the other as the variety . But cases of great difficulty , which I will not here enumerate , sometimes arise in deciding whether or not to rank one form as a variety ...
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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