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 xvii
... varieties . " He extends the same view to animals . The Dean believes that single species of each genus were created in an originally highly plastic condition , and that these have produced , chiefly by intercrossing , but likewise by ...
... varieties . " He extends the same view to animals . The Dean believes that single species of each genus were created in an originally highly plastic condition , and that these have produced , chiefly by intercrossing , but likewise by ...
Página xviii
... varieties slowly become changed into permanent species , which are no longer capable of intercrossing . Rafinesque , in his ' New Flora of North America , ' published in 1836 , wrote ( p . 6 ) as follows : - " All species might have ...
... varieties slowly become changed into permanent species , which are no longer capable of intercrossing . Rafinesque , in his ' New Flora of North America , ' published in 1836 , wrote ( p . 6 ) as follows : - " All species might have ...
Página xxiii
... varieties , and from the principle of general gradation , that species have been modified ; and he attributes the modification to the change of circumstances . The author ( 1855 ) has also treated Psychology on the principle of the ...
... varieties , and from the principle of general gradation , that species have been modified ; and he attributes the modification to the change of circumstances . The author ( 1855 ) has also treated Psychology on the principle of the ...
Página 3
... varieties , from other species . Never- theless , such a conclusion , even if well founded , would be unsatisfactory , until it could be shown how the innumerable species inhabiting this world have been modified , so as to acquire that ...
... varieties , from other species . Never- theless , such a conclusion , even if well founded , would be unsatisfactory , until it could be shown how the innumerable species inhabiting this world have been modified , so as to acquire that ...
Página 5
... varieties when intercrossed ; and fourthly , the imperfec- tion of the Geological Record . In the next chapter I shall consider the geological succession of organic beings throughout time ; in the twelfth and thirteenth , their.
... varieties when intercrossed ; and fourthly , the imperfec- tion of the Geological Record . In the next chapter I shall consider the geological succession of organic beings throughout time ; in the twelfth and thirteenth , their.
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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