The Origin of Species by Means of Natural Selection: Or, the Preservation of Favored Races in the Struggle for Life, Volumen1D. Appleton, 1898 |
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Página 10
... rarely or never seed ! In some few cases it has been discovered that a very trifling change , such as a little more or less water at some particular period of growth , will determine whether or not a plant will produce seeds . I cannot ...
... rarely or never seed ! In some few cases it has been discovered that a very trifling change , such as a little more or less water at some particular period of growth , will determine whether or not a plant will produce seeds . I cannot ...
Página 12
... rarely under nature , but are far from rare under culture . As a single bud out of the many thousands , produced year after year on the same tree under uniform conditions , has been known suddenly to assume a new character ; and as buds ...
... rarely under nature , but are far from rare under culture . As a single bud out of the many thousands , produced year after year on the same tree under uniform conditions , has been known suddenly to assume a new character ; and as buds ...
Página 44
... rarely cares for what is internal . He can never act by selection , excepting on variations which are first given to him in some slight degree by nature . No man would ever try to make a fantail till he saw a pigeon with a tail de ...
... rarely cares for what is internal . He can never act by selection , excepting on variations which are first given to him in some slight degree by nature . No man would ever try to make a fantail till he saw a pigeon with a tail de ...
Página 47
... rarely possess more than one breed of the same species . Pigeons can be mated for life , and this is a great convenience to the fancier , for thus many races may be improved and kept true , though mingled in the same aviary ; and this ...
... rarely possess more than one breed of the same species . Pigeons can be mated for life , and this is a great convenience to the fancier , for thus many races may be improved and kept true , though mingled in the same aviary ; and this ...
Página 51
... rarely be proved . We have also what are called monstrosities ; but they graduate into varieties . By a monstrosity I presume is meant some considerable deviation of structure , generally injurious , or not useful to the species . Some ...
... rarely be proved . We have also what are called monstrosities ; but they graduate into varieties . By a monstrosity I presume is meant some considerable deviation of structure , generally injurious , or not useful to the species . Some ...
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Términos y frases comunes
adapted advantage allied analogous animals and plants appear Asa Gray beak become bees believe birds breeds caudicle cause cells characters climate closely colour common crossed cuckoo degree descendants developed difficulty distinct species disuse divergence domestic animals domestic races doubt effects eggs existence extinct extremely facts favourable females flowers forms Fritz Müller genera genus giraffe gradations greater number groups habits Hence hermaphrodites hive-bee important increase inhabitants inherited insects instance instincts intercrossing intermediate kind lamellæ large number larger genera larvæ less males manner Melipona Mivart modified natural selection naturalists nearly nest occasionally offspring organisation organs origin Origin of Species parent perfect period pigeons pollen pollen-grains present preserved prey principle probably produced progenitor quadrupeds rank rarely Red Grouse relation remarked resemble rock-pigeon seeds sexes sexual selection slight stamens striped structure struggle supposed swimbladder tend tendency tion tree variability variations varieties vary widely wings young