The Origin of Species by Means of Natural Selection: Or, The Preservation of Favoured Races in the Struggle for LifeCollier Books, 1962 - 512 páginas |
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Página 63
... forms ! Amongst animals which unite for each birth , and which are highly locomotive , doubtful forms , ranked by one zoologist as a species and by another as a variety , can rarely be found within the same country , but are common in ...
... forms ! Amongst animals which unite for each birth , and which are highly locomotive , doubtful forms , ranked by one zoologist as a species and by another as a variety , can rarely be found within the same country , but are common in ...
Página 389
... forms living on the lowlands under the equator , would have been driven to their former homes or have been destroyed , being replaced by the equatorial forms returning from the south . Some , however , of the northern temperate forms ...
... forms living on the lowlands under the equator , would have been driven to their former homes or have been destroyed , being replaced by the equatorial forms returning from the south . Some , however , of the northern temperate forms ...
Página 390
... forms having existed in their own homes in greater numbers , and having con- sequently been advanced through natural selection and com- petition to a higher stage of perfection , or dominating power , than the southern forms . And thus ...
... forms having existed in their own homes in greater numbers , and having con- sequently been advanced through natural selection and com- petition to a higher stage of perfection , or dominating power , than the southern forms . And thus ...
Contenido
An Historical Sketch | 15 |
Introduction | 25 |
Variation Under Nature | 58 |
Derechos de autor | |
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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 common continent crossed crustaceans degree developed difficulty distinct species domestic doubt eggs embryo existing extinct extremely facts favourable fertilised fertility flowers formation forms fossil Fritz Müller genera genus geological Glacial period gradations greater number groups of species 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 offspring organisation organs Origin of Species parent peculiar perfect pigeons pistil pollen present principle probably produced progenitor 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