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 34
... compared with the older varieties or with their parent - stocks . No one would ever expect to get a first - rate heartsease or dahlia from the seed of a wild plant . No one would expect to raise a first - rate melting pear from the seed ...
... compared with the older varieties or with their parent - stocks . No one would ever expect to get a first - rate heartsease or dahlia from the seed of a wild plant . No one would expect to raise a first - rate melting pear from the seed ...
Página 35
... comparable with that given to the plants in countries anciently civilised . In regard to the domestic animals kept by uncivilised man , it should not be overlooked that they almost always have to struggle for their own food , at least ...
... comparable with that given to the plants in countries anciently civilised . In regard to the domestic animals kept by uncivilised man , it should not be overlooked that they almost always have to struggle for their own food , at least ...
Página 42
... this nature could have been effected only by slow degrees : yet quite recently Mr. Lubbock has shown a degree of variability in these main nerves in Coccus , which may almost be compared to the 42 ON THE ORIGIN OF SPECIES.
... this nature could have been effected only by slow degrees : yet quite recently Mr. Lubbock has shown a degree of variability in these main nerves in Coccus , which may almost be compared to the 42 ON THE ORIGIN OF SPECIES.
Página 43
... compared to the irregular branching of the stem of a tree . This philosophical naturalist , I may add , has also quite recently shown that the muscles in the larvæ of certain insects are very far from uniform . Authors sometimes argue ...
... compared to the irregular branching of the stem of a tree . This philosophical naturalist , I may add , has also quite recently shown that the muscles in the larvæ of certain insects are very far from uniform . Authors sometimes argue ...
Página 45
... comparing , and seeing others compare , the birds from the separate islands of the Galapagos Archipelago , both one with another , and with those from the American mainland , I was much struck how entirely vague and arbitrary is the ...
... comparing , and seeing others compare , the birds from the separate islands of the Galapagos Archipelago , both one with another , and with those from the American mainland , I was much struck how entirely vague and arbitrary is the ...
Otras ediciones - Ver todas
On the Origin of Species by Means of Natural Selection: or the Preservation ... Charles Darwin Vista previa limitada - 2023 |
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