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 8
... never seed ! In some few such cases it has been discovered that very trifling changes , such as a little more or less water at some particular period of growth , will determine whether or not the plant sets a seed . I cannot here enter ...
... never seed ! In some few such cases it has been discovered that very trifling changes , such as a little more or less water at some particular period of growth , will determine whether or not the plant sets a seed . I cannot here enter ...
Página 26
... never less than 20,000 pigeons were taken with the court . ' The monarchs of Iran and Turan sent him some very rare birds ' ; and , continues the courtly historian , His Majesty by crossing the breeds , which method was never practised ...
... never less than 20,000 pigeons were taken with the court . ' The monarchs of Iran and Turan sent him some very rare birds ' ; and , continues the courtly historian , His Majesty by crossing the breeds , which method was never practised ...
Página 27
... never met a pigeon , or poultry , or duck , or rabbit fancier , who was not fully convinced that each main breed was descended from a distinct species . Van Mons , in his treatise on pears and apples , shows how utterly he disbelieves ...
... never met a pigeon , or poultry , or duck , or rabbit fancier , who was not fully convinced that each main breed was descended from a distinct species . Van Mons , in his treatise on pears and apples , shows how utterly he disbelieves ...
Página 28
... never desire to sit , and with the bantam so small and elegant ; when we compare the host of agricultural , culinary , orchard , and flower- garden races of plants , most useful to man at different seasons and for different purposes ...
... never desire to sit , and with the bantam so small and elegant ; when we compare the host of agricultural , culinary , orchard , and flower- garden races of plants , most useful to man at different seasons and for different purposes ...
Página 31
... never , the case . The laws of correlation of growth , the importance of which should never be overlooked , will ensure some differences ; but , as a general rule , I cannot doubt that the continued selection of slight variations ...
... never , the case . The laws of correlation of growth , the importance of which should never be overlooked , will ensure some differences ; but , as a general rule , I cannot doubt that the continued selection of slight variations ...
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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