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 18
... intermediate between their parents ; and if we account for our several domestic races by this process , we must admit the former existence of the most extreme forms , as the Italian greyhound , bloodhound , bull - dog , etc. , in the ...
... intermediate between their parents ; and if we account for our several domestic races by this process , we must admit the former existence of the most extreme forms , as the Italian greyhound , bloodhound , bull - dog , etc. , in the ...
Página 19
... intermediate between two extremely different races or species , I can hardly believe . Sir J. Sebright ex- pressly experimentised for this object , and failed . The offspring from the first cross between two pure breeds is tolerably and ...
... intermediate between two extremely different races or species , I can hardly believe . Sir J. Sebright ex- pressly experimentised for this object , and failed . The offspring from the first cross between two pure breeds is tolerably and ...
Página 27
... intermediate links in the long lines of descent , yet admit that many of our domestic races have descended from the same parents - may they not learn a lesson of caution , when they deride the idea of species in a state of nature being ...
... intermediate links in the long lines of descent , yet admit that many of our domestic races have descended from the same parents - may they not learn a lesson of caution , when they deride the idea of species in a state of nature being ...
Página 43
... some other forms , or are so closely linked to them by intermediate gradations , that naturalists do not like to rank them as distinct species , V are in several respects the most important for us VARIATION UNDER NATURE 43.
... some other forms , or are so closely linked to them by intermediate gradations , that naturalists do not like to rank them as distinct species , V are in several respects the most important for us VARIATION UNDER NATURE 43.
Página 44
... intermediate links ; nor will the commonly - assumed hybrid nature of the intermediate links always remove the difficulty . In very many cases , however , one form is ranked as a variety of another , not because the intermediate links ...
... intermediate links ; nor will the commonly - assumed hybrid nature of the intermediate links always remove the difficulty . In very many cases , however , one form is ranked as a variety of another , not because the intermediate links ...
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