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 53
... ranges : this statement is indeed scarcely more than a truism , for if a variety were found to have a wider range than that of its supposed parent - species , their denominations ought to be reversed . But there is also reason to ...
... ranges : this statement is indeed scarcely more than a truism , for if a variety were found to have a wider range than that of its supposed parent - species , their denominations ought to be reversed . But there is also reason to ...
Página 54
... range over 7.7 provinces ; whereas , the species to which these varieties belong range over 14.3 provinces . So that the acknow- ledged varieties have very nearly the same restricted average range , as have those very closely allied ...
... range over 7.7 provinces ; whereas , the species to which these varieties belong range over 14.3 provinces . So that the acknow- ledged varieties have very nearly the same restricted average range , as have those very closely allied ...
Página 60
... range in India , as I hear from Dr. Falconer , from Cape Comorin to the Himalaya , which have been imported from America since its discovery . In such cases , and endless instances could be given , no one supposes that the fertility of ...
... range in India , as I hear from Dr. Falconer , from Cape Comorin to the Himalaya , which have been imported from America since its discovery . In such cases , and endless instances could be given , no one supposes that the fertility of ...
Página 65
... range . For in such cases , we may believe , that a plant could exist only where the con- ditions of its life were so favourable that many could exist together , and thus save the species from utter destruction . I should add that the ...
... range . For in such cases , we may believe , that a plant could exist only where the con- ditions of its life were so favourable that many could exist together , and thus save the species from utter destruction . I should add that the ...
Página 71
... range , why does it not double or quadruple its numbers ? We know that it can perfectly well withstand a little more heat or cold , dampness or dryness , for elsewhere it ranges into slightly hotter or colder , damper or drier districts ...
... range , why does it not double or quadruple its numbers ? We know that it can perfectly well withstand a little more heat or cold , dampness or dryness , for elsewhere it ranges into slightly hotter or colder , damper or drier districts ...
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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