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 4
... variability of species in a state of nature ; but I shall , unfortunately , be compelled to treat this subject far too briefly , as it can be treated properly only by giving long catalogues of facts . We shall , however , be en- abled ...
... variability of species in a state of nature ; but I shall , unfortunately , be compelled to treat this subject far too briefly , as it can be treated properly only by giving long catalogues of facts . We shall , however , be en- abled ...
Página 6
... that species . Furthermore , I am convinced that Natural Selection has been the main but not exclusive means of modification . CHAPTER I VARIATION UNDER DOMESTICATION Causes of Variability - Effects 6 ON THE ORIGIN OF SPECIES.
... that species . Furthermore , I am convinced that Natural Selection has been the main but not exclusive means of modification . CHAPTER I VARIATION UNDER DOMESTICATION Causes of Variability - Effects 6 ON THE ORIGIN OF SPECIES.
Página 7
... Variability - Effects of Habit - Correlation of Growth- Inheritance - Character of Domestic Varieties -- Difficulty of dis tinguishing between Varieties and Species - Origin of Domestic Varieties from one or more Species - Domestic ...
... Variability - Effects of Habit - Correlation of Growth- Inheritance - Character of Domestic Varieties -- Difficulty of dis tinguishing between Varieties and Species - Origin of Domestic Varieties from one or more Species - Domestic ...
Página 8
... variability , whatever they may be , generally act ; whether during the early or late period of development of the embryo , or at the instant of conception . Geoffroy St. Hilaire's experiments show that unnatural treatment of the embryo ...
... variability , whatever they may be , generally act ; whether during the early or late period of development of the embryo , or at the instant of conception . Geoffroy St. Hilaire's experiments show that unnatural treatment of the embryo ...
Página 9
... variability to the same cause which produces sterility ; and variability is the source of all the choicest productions of the garden . I may add , that as some organisms will breed freely under the most unnatural conditions ( for ...
... variability to the same cause which produces sterility ; and variability is the source of all the choicest productions of the garden . I may add , that as some organisms will breed freely under the most unnatural conditions ( for ...
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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