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 84
... marked ones , though having some- what of the character of species - as is shown by the hopeless doubts in many ... marked differences ; whereas varieties , the supposed prototypes and parents of future well - marked species , present ...
... marked ones , though having some- what of the character of species - as is shown by the hopeless doubts in many ... marked differences ; whereas varieties , the supposed prototypes and parents of future well - marked species , present ...
Página 92
... marked varieties ; but we have only to suppose the steps in the process of modification to be more numerous or greater in amount , to convert these three forms into well - defined or at least into doubtful species . Thus the diagram ...
... marked varieties ; but we have only to suppose the steps in the process of modification to be more numerous or greater in amount , to convert these three forms into well - defined or at least into doubtful species . Thus the diagram ...
Página 95
... marked a14 to p14 , those marked b11 and f11 , and those marked 014 to m14 , will form three very distinct genera . We shall also have two very distinct genera descended from ( I ) , differing widely from the descendants of ( A ) ...
... marked a14 to p14 , those marked b11 and f11 , and those marked 014 to m14 , will form three very distinct genera . We shall also have two very distinct genera descended from ( I ) , differing widely from the descendants of ( A ) ...
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