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 79
... advantage , the process of modification would be very slow , and there would be simultaneously the most rigorous selection of the young birds within the egg , which had the most powerful and hardest beaks , for all with weak beaks would ...
... advantage , the process of modification would be very slow , and there would be simultaneously the most rigorous selection of the young birds within the egg , which had the most powerful and hardest beaks , for all with weak beaks would ...
Página 81
... advantage over other males , in their weapons , means of defence , or charms ; and have transmitted these advantages to their male offspring . Yet , I would not wish to attri- bute all such sexual differences to this agency for we see ...
... advantage over other males , in their weapons , means of defence , or charms ; and have transmitted these advantages to their male offspring . Yet , I would not wish to attri- bute all such sexual differences to this agency for we see ...
Página 85
... advantage of what has been called the ' physiological division of labour ' ; hence we may believe that it would be advantageous to a plant to produce stamens alone in one flower or on one whole plant , and pistils alone in another ...
... advantage of what has been called the ' physiological division of labour ' ; hence we may believe that it would be advantageous to a plant to produce stamens alone in one flower or on one whole plant , and pistils alone in another ...
Página 86
... advantage to the hive - bee to have a slightly longer or differently constructed proboscis . On the other hand , I have found by experiment that the fertility of clover depends on bees visiting and moving parts of the corolla , so as to ...
... advantage to the hive - bee to have a slightly longer or differently constructed proboscis . On the other hand , I have found by experiment that the fertility of clover depends on bees visiting and moving parts of the corolla , so as to ...
Página 104
... advantages of diversifica- tion of structure , with the accompanying differences of habit and constitution , determine that the inhabitants , which thus jostle each other most closely , shall , as a general rule , belong to what we call ...
... advantages of diversifica- tion of structure , with the accompanying differences of habit and constitution , determine that the inhabitants , which thus jostle each other most closely , shall , as a general rule , belong to what we call ...
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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