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 34
... ranked as a variety of another , not because the intermediate links have actually been found , but because analogy leads the observer to suppose either that they do now somewhere exist , or may formerly have existed ; and here a wide ...
... ranked as a variety of another , not because the intermediate links have actually been found , but because analogy leads the observer to suppose either that they do now somewhere exist , or may formerly have existed ; and here a wide ...
Página 35
... ranked as distinct species by many entomologists . Even Ireland has a few animals , now generally regarded as varieties , but which have been ranked as species by some zoologists . Several experienced ornithologists consider our British ...
... ranked as distinct species by many entomologists . Even Ireland has a few animals , now generally regarded as varieties , but which have been ranked as species by some zoologists . Several experienced ornithologists consider our British ...
Página 36
... ranked by all entomologists as good species . But no observer can determine for another , even if he can do so for himself , which of these Phytophagic forms ought to be called species and which varieties . Mr. Walsh ranks the forms ...
... ranked by all entomologists as good species . But no observer can determine for another , even if he can do so for himself , which of these Phytophagic forms ought to be called species and which varieties . Mr. Walsh ranks the forms ...
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