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
... climate , food , etc. , as the only pos- sible cause of variation . In one very limited sense , as we shall hereafter see , this may be true ; but it is pre- posterous to attribute to mere external conditions the structure , for ...
... climate , food , etc. , as the only pos- sible cause of variation . In one very limited sense , as we shall hereafter see , this may be true ; but it is pre- posterous to attribute to mere external conditions the structure , for ...
Página 7
... climates and treatment , I think we are driven to conclude that this great variability is simply due to our domestic productions having been raised under con- ditions of life not so uniform as , and somewhat different from , those to ...
... climates and treatment , I think we are driven to conclude that this great variability is simply due to our domestic productions having been raised under con- ditions of life not so uniform as , and somewhat different from , those to ...
Página 10
... climate . Habit also has a decided influence , as in the period of flowering with plants when transported from one climate to another . In animals it has a more marked effect ; for instance , I find in the domestic duck that the bones ...
... climate . Habit also has a decided influence , as in the period of flowering with plants when transported from one climate to another . In animals it has a more marked effect ; for instance , I find in the domestic duck that the bones ...
Página 16
... climates . I do not dispute that these capacities have added largely to the value of most of our domesticated productions ; but how could a savage possibly know , when he first tamed an animal , whether it would vary in succeeding ...
... climates . I do not dispute that these capacities have added largely to the value of most of our domesticated productions ; but how could a savage possibly know , when he first tamed an animal , whether it would vary in succeeding ...
Página 56
... climate - Protection from the number of individuals - Complex relations of all animals and plants throughout nature - Struggle for life most severe between individuals and varieties of the same species ; often severe between species of ...
... climate - Protection from the number of individuals - Complex relations of all animals and plants throughout nature - Struggle for life most severe between individuals and varieties of the same species ; often severe between species of ...
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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