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 167
... perfect as , or slightly more perfect than , the other inhabitants of the same country with which it comes into competition . And we see that this is the standard of perfection attained under nature . The endemic productions of New ...
... perfect as , or slightly more perfect than , the other inhabitants of the same country with which it comes into competition . And we see that this is the standard of perfection attained under nature . The endemic productions of New ...
Página 168
... perfect . Can we consider the sting of the bee as perfect , which , when used against many kinds of enemies , cannot be withdrawn , owing to the backward serratures , and thus inevitably causes the death of the insect by tearing out its ...
... perfect . Can we consider the sting of the bee as perfect , which , when used against many kinds of enemies , cannot be withdrawn , owing to the backward serratures , and thus inevitably causes the death of the insect by tearing out its ...
Página 242
... perfect in structure , as far as the microscope reveals . In the first case the two sexual elements which go to form the embryo are perfect ; in the second case they are either not at all developed , or are imperfectly developed . This ...
... perfect in structure , as far as the microscope reveals . In the first case the two sexual elements which go to form the embryo are perfect ; in the second case they are either not at all developed , or are imperfectly developed . This ...
Contenido
VARIATION UNDER NATURE | 30 |
STRUGGLE FOR EXISTENCE | 45 |
NATURAL SELECTION | 59 |
Derechos de autor | |
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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