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 3
... produced perfect as we now see them ; but this assumption seems to me to be no explanation , for it leaves the case of the coadaptations of organic beings to each other and to their physical conditions of life , untouched and ...
... produced perfect as we now see them ; but this assumption seems to me to be no explanation , for it leaves the case of the coadaptations of organic beings to each other and to their physical conditions of life , untouched and ...
Página 9
... producing off- spring not perfectly like their parents . Sterility has been said to be the bane of horticulture ; but on this view we owe variability to the same cause which produces sterility ; and variability is the source of all the ...
... producing off- spring not perfectly like their parents . Sterility has been said to be the bane of horticulture ; but on this view we owe variability to the same cause which produces sterility ; and variability is the source of all the ...
Página 10
... produced very little direct effect , though apparently more in the case of plants . Under this point of view , Mr ... produce similar changes of structure . Nevertheless some slight amount of change may , I think , be attributed to the ...
... produced very little direct effect , though apparently more in the case of plants . Under this point of view , Mr ... produce similar changes of structure . Nevertheless some slight amount of change may , I think , be attributed to the ...
Página 16
... produced under domestica- tion ; I believe that some small part of the difference is due to their being descended from distinct species . In the case of some other domesticated species , there is presumptive , or even strong evidence ...
... produced under domestica- tion ; I believe that some small part of the difference is due to their being descended from distinct species . In the case of some other domesticated species , there is presumptive , or even strong evidence ...
Página 18
... produced by the crossing of a few aboriginal species ; but by crossing we can only get forms in some degree intermediate between their parents ; and if we account for our several domestic races by this process , we must admit the former ...
... produced by the crossing of a few aboriginal species ; but by crossing we can only get forms in some degree intermediate between their parents ; and if we account for our several domestic races by this process , we must admit the former ...
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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