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 140
... intermediate varieties will , it is probable , at first have been formed in the intermediate zones , but they will generally have had a short duration . For these intermediate varieties will , from reasons already assigned ( namely from ...
... intermediate varieties will , it is probable , at first have been formed in the intermediate zones , but they will generally have had a short duration . For these intermediate varieties will , from reasons already assigned ( namely from ...
Página 273
... intermediate forms must , on the theory , have formerly existed . I have extinct intermediate varieties ; on their found it difficult , when looking at any two species , to avoid picturing number to myself forms directly intermediate ...
... intermediate forms must , on the theory , have formerly existed . I have extinct intermediate varieties ; on their found it difficult , when looking at any two species , to avoid picturing number to myself forms directly intermediate ...
Página 315
... intermediate in general character between that which preceded and that which succeeded it . Thus the species which lived at the sixth great stage of descent in the diagram are the modified offspring of those which lived at the fifth ...
... intermediate in general character between that which preceded and that which succeeded it . Thus the species which lived at the sixth great stage of descent in the diagram are the modified offspring of those which lived at the fifth ...
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