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 vii
... 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 Page 164 ...
... 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 Page 164 ...
Página xxv
... 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 6
... manner as the acknowledged varieties of any one species are the de- scendants of that species . Furthermore , I am convinced that Natural Selection has been the most important , but not the exclusive , means of modification . 53 CHAPTER ...
... manner as the acknowledged varieties of any one species are the de- scendants of that species . Furthermore , I am convinced that Natural Selection has been the most important , but not the exclusive , means of modification . 53 CHAPTER ...
Página 8
... 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 8 VARIATION UNDER DOMESTICATION . [ CHAP . I.
... 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 8 VARIATION UNDER DOMESTICATION . [ CHAP . I.
Página 9
... manner . Such facts as the com- plex and extraordinary out - growths which invariably fol low from the insertion of a minute drop of poison by a gall - producing insect , show us what singular modifica- tions might result in the case of ...
... manner . Such facts as the com- plex and extraordinary out - growths which invariably fol low from the insertion of a minute drop of poison by a gall - producing insect , show us what singular modifica- tions might result in the case of ...
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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