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 21
... birds are clothed when hatched . The shape and size of the eggs vary . The 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 ...
... birds are clothed when hatched . The shape and size of the eggs vary . The 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 ...
Página 22
... birds breeding on preci- pices , and good fliers , are unlikely to be exterminated ; and the common rock - pigeon , which has the same habits with the domestic breeds , has not been exter- minated even on several of the smaller British ...
... birds breeding on preci- pices , and good fliers , are unlikely to be exterminated ; and the common rock - pigeon , which has the same habits with the domestic breeds , has not been exter- minated even on several of the smaller British ...
Página 23
... birds , all the above marks , even to the white edging of the outer tail - feathers , sometimes concur perfectly developed . Moreover , when two birds belonging to two distinct breeds are crossed , neither of which is blue or has any of ...
... birds , all the above marks , even to the white edging of the outer tail - feathers , sometimes concur perfectly developed . Moreover , when two birds belonging to two distinct breeds are crossed , neither of which is blue or has any of ...
Página 26
... birds ' ; and , continues the courtly historian , His Majesty by crossing the breeds , which method was never practised before , has improved them astonishingly . ' About this same period the Dutch were as eager about pigeons as were ...
... birds ' ; and , continues the courtly historian , His Majesty by crossing the breeds , which method was never practised before , has improved them astonishingly . ' About this same period the Dutch were as eager about pigeons as were ...
Página 39
... birds may be freely rejected , as when killed they serve for food . On the other hand , cats , from their nocturnal rambling habits , cannot be matched , and , although so much valued by women and children , we hardly ever see a ...
... birds may be freely rejected , as when killed they serve for food . On the other hand , cats , from their nocturnal rambling habits , cannot be matched , and , although so much valued by women and children , we hardly ever see a ...
Otras ediciones - Ver todas
On the Origin of Species by Means of Natural Selection: or the Preservation ... Charles Darwin Vista previa limitada - 2023 |
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