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 xv
... colour of this vigorous race I take for granted , from what has been already said , would be dark . But the same disposition to form varieties still existing , a darker and a darker race would in the course of time occur : and as the ...
... colour of this vigorous race I take for granted , from what has been already said , would be dark . But the same disposition to form varieties still existing , a darker and a darker race would in the course of time occur : and as the ...
Página 6
... colour from the nature of the food , thickness of the skin and hair from climate , & c . Each of the endless variations which we see in the plumage of our fowls must have had some efficient cause ; and if the same cause were to act ...
... colour from the nature of the food , thickness of the skin and hair from climate , & c . Each of the endless variations which we see in the plumage of our fowls must have had some efficient cause ; and if the same cause were to act ...
Página 9
... Colour and constitutional peculiarities go together , of which many remarkable cases could be given amongst animals ... coloured individuals escape : Professor Wyman has recently com- municated to me a good illustration of this fact ; on ...
... Colour and constitutional peculiarities go together , of which many remarkable cases could be given amongst animals ... coloured individuals escape : Professor Wyman has recently com- municated to me a good illustration of this fact ; on ...
Página 19
... colour , with the white loins , double black wing - bar , and barred and white - edged tail feathers , as any wild ... coloured and marked like the rock - pigeon , although no other existing species is thus coloured and marked , so that ...
... colour , with the white loins , double black wing - bar , and barred and white - edged tail feathers , as any wild ... coloured and marked like the rock - pigeon , although no other existing species is thus coloured and marked , so that ...
Página 20
... colour and various black marks in all the breeds , both when kept pure and when crossed ; -and lastly , the mongrel off- spring being perfectly fertile ; -from these several reasons , taker together , we may safely conclude that all our ...
... colour and various black marks in all the breeds , both when kept pure and when crossed ; -and lastly , the mongrel off- spring being perfectly fertile ; -from these several reasons , taker together , we may safely conclude that all our ...
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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