The Origin of Species by Means of Natural Selection,: Or the Preservation of Favoured Races in the Struggle for LifeJohn Murray, Albemarle Street., 1891 - 432 páginas |
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Página 33
... occurs under two distinct forms ; one of these has strong and differently shaped pincers , and the other has antennæ much more abundantly furnished with smelling - hairs . Although in most of these cases , the two or three forms , both ...
... occurs under two distinct forms ; one of these has strong and differently shaped pincers , and the other has antennæ much more abundantly furnished with smelling - hairs . Although in most of these cases , the two or three forms , both ...
Página 36
... occurs with closely allied organisms , which inhabit distinct continents or islands . When , on the other hand , an animal or plant ranges over the same continent , or inhabits many islands in the same archipelago , and presents ...
... occurs with closely allied organisms , which inhabit distinct continents or islands . When , on the other hand , an animal or plant ranges over the same continent , or inhabits many islands in the same archipelago , and presents ...
Página 41
... occur in a group having many species , than in one having few . To test the truth of this anticipation I have arranged the plants of twelve countries , and the coleopterous insects of two districts , into two nearly equal masses , the ...
... occur in a group having many species , than in one having few . To test the truth of this anticipation I have arranged the plants of twelve countries , and the coleopterous insects of two districts , into two nearly equal masses , the ...
Página 51
... occur with our game animals - often ensue ; and here we have a limiting check independent of the struggle for life . But even some of these so - called epidemics appear to be due to parasitic worms , which have from some cause ...
... occur with our game animals - often ensue ; and here we have a limiting check independent of the struggle for life . But even some of these so - called epidemics appear to be due to parasitic worms , which have from some cause ...
Página 57
... occurring in our domestic productions , and , in a lesser degree , in those under nature , be borne in mind ; as well as the strength of the hereditary tendency ... occur under nature . Let it also be. CHAP . IV . ] 57 NATURAL SELECTION .
... occurring in our domestic productions , and , in a lesser degree , in those under nature , be borne in mind ; as well as the strength of the hereditary tendency ... occur under nature . Let it also be. CHAP . IV . ] 57 NATURAL SELECTION .
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Términos y frases comunes
accumulated adapted admit affinities allied species America analogous ancient appear beak become bees believe belonging birds breeds cause cells characters climate closely allied colour continued crossed crustaceans degree developed difficulty distinct species domestic animals doubt effects eggs embryo existing extinct extremely facts favourable female fertilised fertility flowers formation formerly forms fossil Fritz Müller genera genus geological geological period Glacial period gradations greater number habits Hence hybrids 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 occur oceanic islands offspring organisation organs parent peculiar perfect pigeon pistil pollen present preserved principle probably produced quadrupeds ranked reciprocal crosses remarked resemblance rudimentary seeds sexual selection Silurian slight South America stamens sterility structure successive supposed tend theory tion variability variations varieties vary whilst whole wings young