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 10
... 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 , light , food , etc. , is most difficult : my impression is , that with animals ...
... 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 , light , food , etc. , is most difficult : my impression is , that with animals ...
Página 14
... probably do occur ; but natural selection , as will hereafter be explained , will determine how far the new characters thus arising shall be preserved . When we look to the hereditary varieties or races of our domestic animals and ...
... probably do occur ; but natural selection , as will hereafter be explained , will determine how far the new characters thus arising shall be preserved . When we look to the hereditary varieties or races of our domestic animals and ...
Página 18
... probably de- scended from several wild species , I cannot doubt that there has been an immense amount of inherited varia- tion . Who can believe that animals closely resembling the Italian greyhound , the bloodhound , the bull - dog ...
... probably de- scended from several wild species , I cannot doubt that there has been an immense amount of inherited varia- tion . Who can believe that animals closely resembling the Italian greyhound , the bloodhound , the bull - dog ...
Página 27
... probably arisen suddenly , or by one step ; many botanists , for instance , believe that the fuller's teasel , with its hooks , which cannot be rivalled by any mechanical contrivance , is only a variety of the wild Dipsacus ; and this ...
... probably arisen suddenly , or by one step ; many botanists , for instance , believe that the fuller's teasel , with its hooks , which cannot be rivalled by any mechanical contrivance , is only a variety of the wild Dipsacus ; and this ...
Página 28
... probably been with the turnspit dog ; and this is known to have been the case with the ancon sheep . But when we compare the dray - horse and race - horse , the dromedary and camel , the various breeds of sheep fitted either for ...
... probably been with the turnspit dog ; and this is known to have been the case with the ancon sheep . But when we compare the dray - horse and race - horse , the dromedary and camel , the various breeds of sheep fitted either for ...
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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