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 17
... seems to me to be the case , what does it show , but that some of our breeds originated there , four or five thousand years ago ? But Mr. Horner's researches have rendered it in some degree probable that man sufficiently civilised to ...
... seems to me to be the case , what does it show , but that some of our breeds originated there , four or five thousand years ago ? But Mr. Horner's researches have rendered it in some degree probable that man sufficiently civilised to ...
Página 19
... seems simple enough ; but when these mongrels are crossed one with another for several generations , hardly two of them will be alike , and then the extreme difficulty , or rather utter hopelessness , of the task becomes apparent ...
... seems simple enough ; but when these mongrels are crossed one with another for several generations , hardly two of them will be alike , and then the extreme difficulty , or rather utter hopelessness , of the task becomes apparent ...
Página 22
... seems very improbable ; or they must have become extinct in the wild state . But birds breeding on preci- pices , and good fliers , are unlikely to be exterminated ; and the common rock - pigeon , which has the same habits with the ...
... seems very improbable ; or they must have become extinct in the wild state . But birds breeding on preci- pices , and good fliers , are unlikely to be exterminated ; and the common rock - pigeon , which has the same habits with the ...
Página 25
... seems to me rash in the extreme . From these several reasons , namely , the improbability of man having formerly got seven or eight supposed species of pigeons to breed freely under domestica- tion ; these supposed species being quite ...
... seems to me rash in the extreme . From these several reasons , namely , the improbability of man having formerly got seven or eight supposed species of pigeons to breed freely under domestica- tion ; these supposed species being quite ...
Página 43
... seems to me extremely perplexing : I refer to those genera which have sometimes been called ' protean or polymorphic ... seem to be , with some few exceptions , polymorphic in other countries , and likewise , judging from Brachiopod ...
... seems to me extremely perplexing : I refer to those genera which have sometimes been called ' protean or polymorphic ... seem to be , with some few exceptions , polymorphic in other countries , and likewise , judging from Brachiopod ...
Otras ediciones - Ver todas
On the Origin of Species by Means of Natural Selection: or the Preservation ... Charles Darwin Vista previa limitada - 2023 |
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