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 vi
... manner are highly variable ; specific characters more variable than generic : secondary sexual characters variable - Species of the same genus vary in an analogous manner - Reversions to long - lost characters -Summary 98 CHAPTER VI ...
... manner are highly variable ; specific characters more variable than generic : secondary sexual characters variable - Species of the same genus vary in an analogous manner - Reversions to long - lost characters -Summary 98 CHAPTER VI ...
Página xx
... manner by the Rev. Baden Powell , in his ' Essays on the Unity of Worlds , ' 1855. Nothing can be more striking than the manner in which he shows that the introduction of new species is " a regular , not a casual phenomenon , " or , as ...
... manner by the Rev. Baden Powell , in his ' Essays on the Unity of Worlds , ' 1855. Nothing can be more striking than the manner in which he shows that the introduction of new species is " a regular , not a casual phenomenon , " or , as ...
Página 4
... manner as the acknowledged varieties of any one species are the descendants of that species . Furthermore , I am convinced that Natural Selection has been the most important , but not the exclusive , means of modification . CHAPTER I ...
... manner as the acknowledged varieties of any one species are the descendants of that species . Furthermore , I am convinced that Natural Selection has been the most important , but not the exclusive , means of modification . CHAPTER I ...
Página 6
... manner . It is extremely difficult to come to any conclusion in regard to the extent of the changes which have been thus definitely induced . There can , however , be little doubt about many slight changes , -such as size from the ...
... manner . It is extremely difficult to come to any conclusion in regard to the extent of the changes which have been thus definitely induced . There can , however , be little doubt about many slight changes , -such as size from the ...
Página 26
... manner , or a pouter till he saw a pigeon with a crop of somewhat unusual size ; and the more abnormal or unusual any character was when it first appeared , the more likely it would be to catch his attention . But to use such an ...
... manner , or a pouter till he saw a pigeon with a crop of somewhat unusual size ; and the more abnormal or unusual any character was when it first appeared , the more likely it would be to catch his attention . But to use such an ...
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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