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
... common goose has not given rise to any marked varieties ; hence the Thoulouse and the common breed , which differ only in colour , that most fleeting of characters , have lately been exhibited as distinct at our poultry- shows . I think ...
... common goose has not given rise to any marked varieties ; hence the Thoulouse and the common breed , which differ only in colour , that most fleeting of characters , have lately been exhibited as distinct at our poultry- shows . I think ...
Página 41
... common species vary most - Species of the larger genera in any country vary more than the species of the smaller genera - Many of the species of the larger genera resemble varieties in being very closely , but unequally , related to ...
... common species vary most - Species of the larger genera in any country vary more than the species of the smaller genera - Many of the species of the larger genera resemble varieties in being very closely , but unequally , related to ...
Página 44
... common , but sometimes the one first described , as the species , and the other as the variety . But cases of great difficulty , which I will not here enumerate , sometimes occur in deciding whether or not to rank one form as a variety ...
... common , but sometimes the one first described , as the species , and the other as the variety . But cases of great difficulty , which I will not here enumerate , sometimes occur in deciding whether or not to rank one form as a variety ...
Página 45
... common in separated areas . How many of those birds and insects in North America and Europe , which differ very slightly from each other , have been ranked by one eminent naturalist as undoubted species , and by another as varieties ...
... common in separated areas . How many of those birds and insects in North America and Europe , which differ very slightly from each other , have been ranked by one eminent naturalist as undoubted species , and by another as varieties ...
Página 46
... common parents , and consequently must be ranked as varieties . Close investigation , in most cases , will bring natural- ists to an agreement how to rank doubtful forms . Yet it must be confessed that it is in the best - known ...
... common parents , and consequently must be ranked as varieties . Close investigation , in most cases , will bring natural- ists to an agreement how to rank doubtful forms . Yet it must be confessed that it is in the best - known ...
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