On the Origin of Species by Means of Natural Selection: Or The Preservation of Favoured Races in the Struggle for LifeHumphrey Milford, Oxford University Press, 1923 - 454 páginas |
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Página 20
... manner . The number of the caudal and sacral vertebræ vary ; as does the number of the ribs , together with their relative breadth and the presence of processes . The size and shape of the apertures in the sternum are highly variable ...
... manner . The number of the caudal and sacral vertebræ vary ; as does the number of the ribs , together with their relative breadth and the presence of processes . The size and shape of the apertures in the sternum are highly variable ...
Página 21
... manner of flight differs remarkably ; as does in some breeds the voice and disposition . Lastly , in certain breeds , the males and females have come to differ to a slight degree from each other . Altogether at least a score of pigeons ...
... manner of flight differs remarkably ; as does in some breeds the voice and disposition . Lastly , in certain breeds , the males and females have come to differ to a slight degree from each other . Altogether at least a score of pigeons ...
Página 36
... manner , or a pouter till he saw a pigeon with a crop of somewhat unusual size ; and the more abnormal or unusual any character was when it first appeared , the more likely it would be to catch his attention . But to use such an ...
... manner , or a pouter till he saw a pigeon with a crop of somewhat unusual size ; and the more abnormal or unusual any character was when it first appeared , the more likely it would be to catch his attention . But to use such an ...
Página 42
... manner as man can accumu- late in any given direction individual differences in his domesticated productions . These individual differences generally affect what naturalists consider unimportant parts ; but I could show by a long ...
... manner as man can accumu- late in any given direction individual differences in his domesticated productions . These individual differences generally affect what naturalists consider unimportant parts ; but I could show by a long ...
Página 53
... manner as the varieties of any one species are related to each other . No natur- alist pretends that all the species of a genus are equally distinct from each other ; they may generally be divided into sub - genera , or sections , or ...
... manner as the varieties of any one species are related to each other . No natur- alist pretends that all the species of a genus are equally distinct from each other ; they may generally be divided into sub - genera , or sections , or ...
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Términos y frases comunes
accumulated adapted affinities allied species America amount analogous ancient appear Archipelago become bees believe birds breeds cause cells characters cirripedes climate closely allied colour common parent continuous crossed crustaceans degree difficulty distinct species divergence doubt embryo endemic Europe existing exterminated extinct extremely facts favourable fertility flowers formations forms fossil Gärtner genera genus geological geological period Glacial period gradations greater number groups of species habits Hence hermaphrodites hybrids hybrids produced important individuals inhabitants inherited insects instance instincts intercrossing land larvæ less living male mammals manner Marsupials migration modification modified descendants natural selection naturalists nearly nest oceanic islands offspring organisation perfect pigeons pistil plants pollen present principle probably produced progenitor ranked reciprocal crosses remarked resemble rock-pigeon rudimentary organs seeds sexual selection Silurian slight South America sterility structure struggle successive suppose swimbladder tend theory tion trees variability variation vary whole widely