On the Origin of Species by Means of Natural Selection: Or, The Preservation of Favoured Races in the Struggle for LifeEaston Press, 1976 - 470 páginas |
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Página 31
... important parts of structure , which he could collect on good authority , as I have collected , during a course of years . It should be remembered that systematists are far from being pleased at finding variability in important ...
... important parts of structure , which he could collect on good authority , as I have collected , during a course of years . It should be remembered that systematists are far from being pleased at finding variability in important ...
Página 32
... important organs never vary ; for these same authors practically rank those parts as important ( as some few naturalists have honestly confessed ) which do not vary ; and , under this point of view , no instance will ever be found of an ...
... important organs never vary ; for these same authors practically rank those parts as important ( as some few naturalists have honestly confessed ) which do not vary ; and , under this point of view , no instance will ever be found of an ...
Página 80
... important part in modifying species , as if all the forms of life were necessarily undergoing change through some innate law . Lapse of time is only so far important , and its importance in this respect is great , that it gives a better ...
... important part in modifying species , as if all the forms of life were necessarily undergoing change through some innate law . Lapse of time is only so far important , and its importance in this respect is great , that it gives a better ...
Contenido
VARIATION UNDER NATURE | 30 |
STRUGGLE FOR EXISTENCE | 45 |
NATURAL SELECTION | 59 |
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Términos y frases comunes
accumulated adapted admit affinities allied species America ancient appear beak become bees believe belonging birds breeds cause cells characters climate closely allied colour common progenitor continuous crossed crustaceans degree developed difficulty distinct species divergence doubt effects eggs embryo existing exterminated extinct extremely facts favourable fertilised fertility flowers formation forms fossil Fritz Müller genera genus geological geological period gradations greater number groups of species habits Hence hybrids hybrids produced important increase individuals inhabitants inherited insects instance instincts intercrossing intermediate kind lamellæ larvæ less living male mammals manner marsupials migration modified descendants natural selection naturalists nearly nest occasionally offspring organisation organs Origin of Species parent peculiar perfect pigeons pistil plants pollen present preserved principle probably produced quadrupeds ranked reciprocal crosses remarked resemblance rudimentary seeds slight South America stamens sterility structure struggle successive supposed swimbladder theory variability variations varieties vary whilst whole wings young