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 8
... action of any change in the conditions of life . Nothing is more easy than to tame an animal , and few things more difficult than to get it to breed freely under confinement , even in the many cases when the male and female unite . How ...
... action of any change in the conditions of life . Nothing is more easy than to tame an animal , and few things more difficult than to get it to breed freely under confinement , even in the many cases when the male and female unite . How ...
Página 10
... action of the conditions ' been direct , if any of the young had varied , all would probably have varied in the same manner . To judge how much , in the case of any variation , we should attribute to the direct action of heat , moisture ...
... action of the conditions ' been direct , if any of the young had varied , all would probably have varied in the same manner . To judge how much , in the case of any variation , we should attribute to the direct action of heat , moisture ...
Página 14
... action of the poor soil ) , that they would to a large extent , or even wholly , revert to the wild aboriginal stock . Whether or not the experi- ment would succeed , is not of great importance for our line of argument ; for by the ...
... action of the poor soil ) , that they would to a large extent , or even wholly , revert to the wild aboriginal stock . Whether or not the experi- ment would succeed , is not of great importance for our line of argument ; for by the ...
Página 27
... action of the external conditions of life , and some little to habit ; but he would be a bold man who would account by such agencies for the differences of a dray and a race horse , a greyhound and bloodhound , a carrier and tumbler ...
... action of the external conditions of life , and some little to habit ; but he would be a bold man who would account by such agencies for the differences of a dray and a race horse , a greyhound and bloodhound , a carrier and tumbler ...
Página 39
... action on the reproductive system , are so far of the highest importance as causing variability . I do not believe that variability is an inherent and necessary contingency , under all circumstances , with all organic beings , as some ...
... action on the reproductive system , are so far of the highest importance as causing variability . I do not believe that variability is an inherent and necessary contingency , under all circumstances , with all organic beings , as 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