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 3
... modification and co- adaptation . At the commencement of my observations it seemed to me probable that a careful study of domes ticated animals and of cultivated plants would offer the best chance of making out this obscure problem ...
... modification and co- adaptation . At the commencement of my observations it seemed to me probable that a careful study of domes ticated animals and of cultivated plants would offer the best chance of making out this obscure problem ...
Página 4
... modification is at least possible ; and , what is equally or more important , we shall see how great is the power of man in accumulating by his Selection successive slight variations . I will then pass on to the variability of species ...
... modification is at least possible ; and , what is equally or more important , we shall see how great is the power of man in accumulating by his Selection successive slight variations . I will then pass on to the variability of species ...
Página 8
... modification . It has been disputed at what period of life the causes of 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 ...
... modification . It has been disputed at what period of life the causes of 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 ...
Página 41
... modification directly due to the physical conditions of life ; and ' variations ' in this sense are supposed not to be inherited : but who can say that the dwarfed condition of shells in the brackish waters of the 41 VARIATION UNDER NATURE.
... modification directly due to the physical conditions of life ; and ' variations ' in this sense are supposed not to be inherited : but who can say that the dwarfed condition of shells in the brackish waters of the 41 VARIATION UNDER NATURE.
Página 74
... modification , which in the course of ages chanced to arise , and which in any way favoured the individuals of any of the species , by better adapting them to their altered conditions , would tend to be pre- served ; and natural ...
... modification , which in the course of ages chanced to arise , and which in any way favoured the individuals of any of the species , by better adapting them to their altered conditions , would tend to be pre- served ; and natural ...
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