The Origin of Species by Means of Natural Selection: Or the Preservation of Favored Races in the Struggle for LifeD. Appleton, 1904 - 435 páginas |
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Página v
... smaller genera - Many of the species of the larger genera resemble varieties in being very closely , but unequally , related to each other , and in having restricted ranges • . 51 CHAPTER III . STRUGGLE FOR EXISTENCE . Its bearing on.
... smaller genera - Many of the species of the larger genera resemble varieties in being very closely , but unequally , related to each other , and in having restricted ranges • . 51 CHAPTER III . STRUGGLE FOR EXISTENCE . Its bearing on.
Página xi
... range of a species of Galaxias , a fresh - water fish . Discussion on analogical resemblances , enlarged and modified . Homological structure of the feet of certain mar- supial animals . On serial homologies , corrected . Mr. E. Ray ...
... range of a species of Galaxias , a fresh - water fish . Discussion on analogical resemblances , enlarged and modified . Homological structure of the feet of certain mar- supial animals . On serial homologies , corrected . Mr. E. Ray ...
Página 6
... ranges widely and is very numerous , and why another allied species has a narrow range and is rare ? Yet these relations are of the highest importance , for they determine the present welfare and , as I believe , the future success and ...
... ranges widely and is very numerous , and why another allied species has a narrow range and is rare ? Yet these relations are of the highest importance , for they determine the present welfare and , as I believe , the future success and ...
Página 51
... ranges . BEFORE applying the principles arrived at in the last chapter to organic beings in a state of nature , we must briefly discuss whether these latter are subject to any variation . To treat this subject properly , a long ...
... ranges . BEFORE applying the principles arrived at in the last chapter to organic beings in a state of nature , we must briefly discuss whether these latter are subject to any variation . To treat this subject properly , a long ...
Página 55
... dations , it is probable that they were once thus con- nected . Mr. Wallace , for instance , describes a certain . butterfly which presents in the same island a great range 6 CHAP . II . ] 55 INDIVIDUAL DIFFERENCES .
... dations , it is probable that they were once thus con- nected . Mr. Wallace , for instance , describes a certain . butterfly which presents in the same island a great range 6 CHAP . II . ] 55 INDIVIDUAL DIFFERENCES .
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Términos y frases comunes
adapted affinities allied species America ancient appear Asa Gray beak become bees believe belonging birds breeds cause cells characters climate closely allied colour common continent crossed crustaceans degree developed difficulty distinct species domestic doubt effects eggs embryo existing extinct extremely facts favourable fertilised fertility flowers formation forms fossil Fritz Müller genera genus geological geological period Glacial period gradations greater number groups of species habits Hence hybrids important individuals inhabitants inherited insects instance instincts intercrossing intermediate kind lamellæ larvæ less living males mammals manner marsupials migration modified descendants natural selection naturalists nearly nest occasionally offspring organisation organs parent peculiar perfect pigeon pistil pollen present principle probably produced progenitor quadrupeds ranked remarked resemblance rudimentary seeds sexual selection Silurian slight South America stamens sterility structure successive supposed swimbladder tend theory tion trees variability variations varieties vary whilst whole wings young