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 7
... Domestic Varieties from one or more Species - Domestic Pigeons , their Differences and Origin - Principle of Selection anciently followed , its Effects - Methodical and Unconscious Selection - Unknown Origin of our Domestic Productions ...
... Domestic Varieties from one or more Species - Domestic Pigeons , their Differences and Origin - Principle of Selection anciently followed , its Effects - Methodical and Unconscious Selection - Unknown Origin of our Domestic Productions ...
Página 10
... domestic duck that the bones of the wing weigh less and the bones of the leg more , in proportion to the whole skeleton , than do the same bones in the wild - duck ; and I presume that this change may be safely attributed to the domestic ...
... domestic duck that the bones of the wing weigh less and the bones of the leg more , in proportion to the whole skeleton , than do the same bones in the wild - duck ; and I presume that this change may be safely attributed to the domestic ...
Página 11
... domestic animal can be named which has not in some country drooping ears ; and the view suggested by some authors , that the drooping is due to the disuse of the muscles of the ear , from the animals not being much alarmed by danger ...
... domestic animal can be named which has not in some country drooping ears ; and the view suggested by some authors , that the drooping is due to the disuse of the muscles of the ear , from the animals not being much alarmed by danger ...
Página 13
... domestic breeds are often trans- mitted either exclusively , or in a much greater degree , to males alone . A much ... domestic varieties , when run wild , gradually but certainly revert in character to their aboriginal stocks . Hence it ...
... domestic breeds are often trans- mitted either exclusively , or in a much greater degree , to males alone . A much ... domestic varieties , when run wild , gradually but certainly revert in character to their aboriginal stocks . Hence it ...
Página 14
... domestic varieties could not possibly live in a wild state . In many cases we do not know what the aboriginal stock was , and so could not tell whether or not nearly perfect reversion had ensued . It would be quite necessary , in order ...
... domestic varieties could not possibly live in a wild state . In many cases we do not know what the aboriginal stock was , and so could not tell whether or not nearly perfect reversion had ensued . It would be quite necessary , in order ...
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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