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 27
... allied species . Some little effect may , perhaps , be attributed to the direct 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 ...
... allied species . Some little effect may , perhaps , be attributed to the direct 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 ...
Página 29
... allied sub- breeds . And when a cross has been made , the closest selection is far more indispensable even than in ordi- nary cases . If selection consisted merely in separating some very distinct variety , and breeding from it , the ...
... allied sub- breeds . And when a cross has been made , the closest selection is far more indispensable even than in ordi- nary cases . If selection consisted merely in separating some very distinct variety , and breeding from it , the ...
Página 44
... allied forms have permanently retained their characters in their own country for a long time ; for as long , as far as we know , as have good and true species . Practically , when a naturalist can unite two forms together by others ...
... allied forms have permanently retained their characters in their own country for a long time ; for as long , as far as we know , as have good and true species . Practically , when a naturalist can unite two forms together by others ...
Página 47
... allied forms . But if his observations be widely extended , he will in the end generally be enabled to make up his own mind which to call varieties and which species ; but he will succeed in this at the expense of admitting much ...
... allied forms . But if his observations be widely extended , he will in the end generally be enabled to make up his own mind which to call varieties and which species ; but he will succeed in this at the expense of admitting much ...
Página 53
... allied to other species , and in so far resemble varieties , often have much restricted ranges . For instance , Mr. H. C. Watson has marked for me in the well - sifted London Catalogue of plants ( 4th edition ) 63 plants which are し ...
... allied to other species , and in so far resemble varieties , often have much restricted ranges . For instance , Mr. H. C. Watson has marked for me in the well - sifted London Catalogue of plants ( 4th edition ) 63 plants which are し ...
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