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 16
... breeds of the dog has been 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 ...
... breeds of the dog has been 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 ...
Página 17
... breeds ; and that some of the breeds closely resemble , perhaps are identical with , those still existing . Even if this latter fact were found more strictly and generally true than seems to me to be the case , what does it show , but ...
... breeds ; and that some of the breeds closely resemble , perhaps are identical with , those still existing . Even if this latter fact were found more strictly and generally true than seems to me to be the case , what does it show , but ...
Página 18
... breeds of which differ con- siderably from each other in structure , I do not doubt that they have all descended from the common wild duck and rabbit . The doctrine of the origin of our several domestic races from several aboriginal ...
... breeds of which differ con- siderably from each other in structure , I do not doubt that they have all descended from the common wild duck and rabbit . The doctrine of the origin of our several domestic races from several aboriginal ...
Página 19
... breed intermediate between two very distinct breeds could not be got without extreme care and long - continued selection ; nor can I find a single case on record of a permanent race having been thus formed . On the Breeds of the ...
... breed intermediate between two very distinct breeds could not be got without extreme care and long - continued selection ; nor can I find a single case on record of a permanent race having been thus formed . On the Breeds of the ...
Página 20
... breeds of runts have very long necks , others very long wings and tails , others singularly short tails . The barb is allied to the carrier , but , instead of a very long beak , has a very short and very broad one . The pouter has a ...
... breeds of runts have very long necks , others very long wings and tails , others singularly short tails . The barb is allied to the carrier , but , instead of a very long beak , has a very short and very broad one . The pouter has a ...
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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