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 12
... species , then such facts would have great weight in making us doubt about the immuta- bility of the many closely allied natural species - for instance , of the many foxes - inhabiting different quarters of the world . I do not believe ...
... species , then such facts would have great weight in making us doubt about the immuta- bility of the many closely allied natural species - for instance , of the many foxes - inhabiting different quarters of the world . I do not believe ...
Página 18
... species of 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 ...
... species of 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 ...
Página 30
... species appears to have played an important part in the origin of our breeds . When several breeds have once been ... species - Wide ranging , much diffused , and common species , vary most - Species of the larger genera in each country ...
... species appears to have played an important part in the origin of our breeds . When several breeds have once been ... species - Wide ranging , much diffused , and common species , vary most - Species of the larger genera in each country ...
Página 33
... species often present , as is known to every one , great differences of structure , independently of varia- tion , as in the two sexes of various animals , in the two or three castes of sterile female or workers amongst insects , and in ...
... species often present , as is known to every one , great differences of structure , independently of varia- tion , as in the two sexes of various animals , in the two or three castes of sterile female or workers amongst insects , and in ...
Página 34
... species . Practically , when a naturalist can unite by means of intermediate links any two forms , he treats the one as a variety of the other ; ranking the most common , but sometimes the one first described , as the species , and the ...
... species . Practically , when a naturalist can unite by means of intermediate links any two forms , he treats the one as a variety of the other ; ranking the most common , but sometimes the one first described , as the species , and 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