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 viii
... land , and by occasional means --Dispersal during the Glacial period Alternate Glacial periods in - the north and south .. 316-342 ― CHAPTER XIII . GEOGRAPHICAL DISTRIBUTION - continued . Distribution of fresh - water productions -- On ...
... land , and by occasional means --Dispersal during the Glacial period Alternate Glacial periods in - the north and south .. 316-342 ― CHAPTER XIII . GEOGRAPHICAL DISTRIBUTION - continued . Distribution of fresh - water productions -- On ...
Página 22
... land or mountain pasture , with the wool of one breed good for one purpose , and that of another breed for another purpose ; when we compare the many breeds of dogs , each good for man in different ways ; when we compare the game - cock ...
... land or mountain pasture , with the wool of one breed good for one purpose , and that of another breed for another purpose ; when we compare the many breeds of dogs , each good for man in different ways ; when we compare the game - cock ...
Página 30
... land plays a part . Wandering savages or the in- habitants of open plains rarely possess more than one breed of the same species . Pigeons can be mated for life , and this is a great convenience to the fancier , for thus many races may ...
... land plays a part . Wandering savages or the in- habitants of open plains rarely possess more than one breed of the same species . Pigeons can be mated for life , and this is a great convenience to the fancier , for thus many races may ...
Página 38
... land , I was much struck how entirely vague and arbitrary is the distinction between species and varieties . On the islets of the little Madeira group there are many insects which are charac- terized as varieties in Mr. Wollaston's ...
... land , I was much struck how entirely vague and arbitrary is the distinction between species and varieties . On the islets of the little Madeira group there are many insects which are charac- terized as varieties in Mr. Wollaston's ...
Página 42
... land- shells in Madeira , and with plants by Gaston de Saporta . If a variety were to flourish so as to exceed in numbers the parent species , it would them rank as the species , and the species as the variety ; or it might come to ...
... land- shells in Madeira , and with plants by Gaston de Saporta . If a variety were to flourish so as to exceed in numbers the parent species , it would them rank as the species , and the species as the variety ; or it might come to ...
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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