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
... greater degree , to males alone . A much more important rule , which I think may be trusted , is that , at whatever period of life a peculiarity appears , it tends to appear in the offspring at a corresponding age , though sometimes ...
... greater degree , to males alone . A much more important rule , which I think may be trusted , is that , at whatever period of life a peculiarity appears , it tends to appear in the offspring at a corresponding age , though sometimes ...
Página 24
... greater number of genera- tions . In a breed which has been crossed only once with some distinct breed , the tendency to reversion to any character derived from such cross will naturally become less and less , as in each succeeding ...
... greater number of genera- tions . In a breed which has been crossed only once with some distinct breed , the tendency to reversion to any character derived from such cross will naturally become less and less , as in each succeeding ...
Página 45
... greater number rank it as an undoubted species peculiar to Great Britain . A wide distance between the homes of two doubtful forms leads many naturalists to rank both as distinct species ; but what distance , it has been well asked ...
... greater number rank it as an undoubted species peculiar to Great Britain . A wide distance between the homes of two doubtful forms leads many naturalists to rank both as distinct species ; but what distance , it has been well asked ...
Página 47
... greater number of closely - allied forms . But if his observations be widely extended , he will in the end generally be enabled to make up his own mind which to call varieties and which species ; but he will succeed in this at the ...
... greater number of closely - allied forms . But if his observations be widely extended , he will in the end generally be enabled to make up his own mind which to call varieties and which species ; but he will succeed in this at the ...
Página 53
... greater than the average are now manufacturing , many of the species already manufactured still to a certain extent resemble varieties , for they differ from each other by a less than usual amount of difference . Moreover , the species ...
... greater than the average are now manufacturing , many of the species already manufactured still to a certain extent resemble varieties , for they differ from each other by a less than usual amount of difference . Moreover , the species ...
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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