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 36
... individuals of other and distinct breeds , in which as many as seventeen tail - feathers have been counted . Perhaps the first pouter - pigeon did not inflate its crop much more than the turbit now does the upper part of its oesophagus ...
... individuals of other and distinct breeds , in which as many as seventeen tail - feathers have been counted . Perhaps the first pouter - pigeon did not inflate its crop much more than the turbit now does the upper part of its oesophagus ...
Página 37
... individual with some slight deviation of structure , or takes more care than usual in matching his best animals and thus improves them , and the improved individuals slowly spread in the immediate neighbourhood . But as yet they will ...
... individual with some slight deviation of structure , or takes more care than usual in matching his best animals and thus improves them , and the improved individuals slowly spread in the immediate neighbourhood . But as yet they will ...
Página 38
... individuals of a species in any country requires that the species should be placed under favourable conditions of life , so as to breed freely in that country . When the individuals of any species are scanty , all the individuals ...
... individuals of a species in any country requires that the species should be placed under favourable conditions of life , so as to breed freely in that country . When the individuals of any species are scanty , all the individuals ...
Página 42
... individuals of the same species are cast in the very same mould . These individual differences are highly important for us , as they afford materials for natural selection to accumulate , in the same manner as man can accumu- late in ...
... individuals of the same species are cast in the very same mould . These individual differences are highly important for us , as they afford materials for natural selection to accumulate , in the same manner as man can accumu- late in ...
Página 43
... individual differ- ences which seems to me extremely perplexing : I refer to those genera which have sometimes been called ' protean or polymorphic , ' in which the species present an inordinate amount of variation ; and hardly two ...
... individual differ- ences which seems to me extremely perplexing : I refer to those genera which have sometimes been called ' protean or polymorphic , ' in which the species present an inordinate amount of variation ; and hardly two ...
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