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 28
... land or mountain pasture , with the wool of one breed good for one purpose , and that of another breed for another purpose ; when we compare the many breeds of dogs , each good for man in very different ways ; when we compare the game ...
... land or mountain pasture , with the wool of one breed good for one purpose , and that of another breed for another purpose ; when we compare the many breeds of dogs , each good for man in very different ways ; when we compare the game ...
Página 38
... land plays a part . Wandering savages or the inhabitants of open plains 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 ...
... land plays a part . Wandering savages or the inhabitants of open plains 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 ...
Página 48
... land - shells in Madeira . If a variety were to flourish so as to exceed in numbers the parent species , it would then rank as the species , and the species as the variety ; or it might come to supplant and exterminate the parent ...
... land - shells in Madeira . If a variety were to flourish so as to exceed in numbers the parent species , it would then rank as the species , and the species as the variety ; or it might come to supplant and exterminate the parent ...
Página 66
... land had been enclosed , so that cattle could not enter . But how important an element enclosure is , I plainly saw near Farnham , in Surrey . Here there are extensive heaths , with a few clumps of old Scotch firs on the distant hill ...
... land had been enclosed , so that cattle could not enter . But how important an element enclosure is , I plainly saw near Farnham , in Surrey . Here there are extensive heaths , with a few clumps of old Scotch firs on the distant hill ...
Página 67
... land was enclosed , it be- came thickly clothed with vigorously growing young firs . Yet the heath was so extremely barren and so extensive that no one would ever have imagined that cattle would have so closely and effectually searched ...
... land was enclosed , it be- came thickly clothed with vigorously growing young firs . Yet the heath was so extremely barren and so extensive that no one would ever have imagined that cattle would have so closely and effectually searched ...
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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