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 71
... land being already thickly clothed by other plants ; so that the seeds may be widely distributed and fall on unoccupied ground . In the water - beetle , the structure of its legs , so well adapted for diving , allows it to compete with ...
... land being already thickly clothed by other plants ; so that the seeds may be widely distributed and fall on unoccupied ground . In the water - beetle , the structure of its legs , so well adapted for diving , allows it to compete with ...
Página 72
... land may be extremely cold or dry , yet there will be competition between some few species , or between the individuals of the same species , for the warmest or dampest spots . Hence , also , we can see that when a plant or animal is ...
... land may be extremely cold or dry , yet there will be competition between some few species , or between the individuals of the same species , for the warmest or dampest spots . Hence , also , we can see that when a plant or animal is ...
Página 75
... land . And as foreigners have thus everywhere beaten some of the natives , we may safely conclude that the natives might have been modi- fied with advantage , so as to have better resisted such intruders . For As man can produce and ...
... land . And as foreigners have thus everywhere beaten some of the natives , we may safely conclude that the natives might have been modi- fied with advantage , so as to have better resisted such intruders . For As man can produce and ...
Página 91
... land there are some hermaphrodites , as land - mollusca and earth - worms ; but these all pair . As yet I have not found a single case of a terrestrial animal which fertilises itself . We can understand this remarkable fact , which ...
... land there are some hermaphrodites , as land - mollusca and earth - worms ; but these all pair . As yet I have not found a single case of a terrestrial animal which fertilises itself . We can understand this remarkable fact , which ...
Página 95
... land , etc .; and thus new places in the natural economy of the country are left open for the old inhabitants to struggle for , and become adapted to , through modifications in their structure and constitution . Lastly , isolation , by ...
... land , etc .; and thus new places in the natural economy of the country are left open for the old inhabitants to struggle for , and become adapted to , through modifications in their structure and constitution . Lastly , isolation , by ...
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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