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 13
... offspring at a corresponding age , though sometimes earlier . many cases this could not be otherwise : thus the inherited peculiarities in the horns of cattle could appear only in the offspring when nearly mature ; peculiarities in the ...
... offspring at a corresponding age , though sometimes earlier . many cases this could not be otherwise : thus the inherited peculiarities in the horns of cattle could appear only in the offspring when nearly mature ; peculiarities in the ...
Página 16
... offspring of any single species , then such facts would have great weight in making us doubt about the immutability of the many very closely - allied natural species - for instance , of the many foxes - inhabiting different quarters of ...
... offspring of any single species , then such facts would have great weight in making us doubt about the immutability of the many very closely - allied natural species - for instance , of the many foxes - inhabiting different quarters of ...
Página 19
... offspring from the first cross between two pure breeds is tolerably and sometimes ( as I have found with pigeons ) extremely uniform , and everything seems simple enough ; but when these mongrels are crossed one with another for several ...
... offspring from the first cross between two pure breeds is tolerably and sometimes ( as I have found with pigeons ) extremely uniform , and everything seems simple enough ; but when these mongrels are crossed one with another for several ...
Página 23
... offspring are very apt suddenly to acquire these characters ; for instance , I crossed some uniformly white fantails with some uniformly black barbs , and they produced mottled brown and black birds ; these I again crossed together ...
... offspring are very apt suddenly to acquire these characters ; for instance , I crossed some uniformly white fantails with some uniformly black barbs , and they produced mottled brown and black birds ; these I again crossed together ...
Página 24
... offspring of two animals clearly distinct being themselves perfectly fertile . Some authors believe that long - continued domestication eliminates this strong tendency to sterility : from the history of the dog I think there is some ...
... offspring of two animals clearly distinct being themselves perfectly fertile . Some authors believe that long - continued domestication eliminates this strong tendency to sterility : from the history of the dog I think there is some ...
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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