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 69
... kind . This is rather an extreme estimate for most of the higher animals , but by no means so for many of the lower organisms . He then shows that if a single individual were born , which varied in some manner , giving it twice as good ...
... kind . This is rather an extreme estimate for most of the higher animals , but by no means so for many of the lower organisms . He then shows that if a single individual were born , which varied in some manner , giving it twice as good ...
Página 150
... kind . Numerous cases could be given amongst the lower animals of the same organ performing at the same time wholly distinct functions ; thus in the larva of the dragon - fly and in the fish Cobites the alimentary canal respires ...
... kind . Numerous cases could be given amongst the lower animals of the same organ performing at the same time wholly distinct functions ; thus in the larva of the dragon - fly and in the fish Cobites the alimentary canal respires ...
Página 165
... kind open and coloured so as to attract insects ; the other closed , not coloured , destitute of nectar , and never visited by insects . Hence we may conclude that , if insects had not been developed on the face of the earth , our ...
... kind open and coloured so as to attract insects ; the other closed , not coloured , destitute of nectar , and never visited by insects . Hence we may conclude that , if insects had not been developed on the face of the earth , our ...
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