On the Origin of Species by Means of Natural Selection: Or The Preservation of Favored Races in the Struggle for Life, Volumen2D. Appleton, 1888 - 458 páginas |
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Página xiv
... seems to have been chiefly led to his conclusion on the gradual change of species , by the difficulty of distinguishing species and varieties , by the almost perfect gradation of forms in certain groups , and by the analogy of domestic ...
... seems to have been chiefly led to his conclusion on the gradual change of species , by the difficulty of distinguishing species and varieties , by the almost perfect gradation of forms in certain groups , and by the analogy of domestic ...
Página xv
... seems to be done with equal efficacy , though more slowly , by nature , in the formation of varieties of mankind , fitted for the country which they inhabit . Of the acci- dental varieties of man , which would occur among the first few ...
... seems to be done with equal efficacy , though more slowly , by nature , in the formation of varieties of mankind , fitted for the country which they inhabit . Of the acci- dental varieties of man , which would occur among the first few ...
Página xvi
... seems to consider that the world was nearly depopulated at successive periods , and then re - stocked ; and he gives as an alternative , that new forms may be generated " without the presence of any mould or germ of former aggregates ...
... seems to consider that the world was nearly depopulated at successive periods , and then re - stocked ; and he gives as an alternative , that new forms may be generated " without the presence of any mould or germ of former aggregates ...
Página xviii
... seems to me perfectly just , from a passage beginning with the words " no doubt the type - form , " & c . ( Ibid . vol . i . p . xxxv . ) , that Professor Owen admitted that natural selection may have done something in the formation of ...
... seems to me perfectly just , from a passage beginning with the words " no doubt the type - form , " & c . ( Ibid . vol . i . p . xxxv . ) , that Professor Owen admitted that natural selection may have done something in the formation of ...
Página 5
... seems clear that organic beings must be exposed during several generations to new conditions to cause any great amount of varia- tion ; and that , when the organisation has once begun to vary , it generally continues varying for many ...
... seems clear that organic beings must be exposed during several generations to new conditions to cause any great amount of varia- tion ; and that , when the organisation has once begun to vary , it generally continues varying for many ...
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Términos y frases comunes
adapted admit affinities allied species America analogous ancient appear Asa Gray beak become bees believe belonging birds breeds cause cells characters climate closely allied colour continued crossed crustaceans degree developed difficulty distinct species doubt effects eggs embryo existing extinct extremely facts favourable fertilised fertility flowers formation formerly forms fossil Fritz Müller genera genus geological geological period Glacial period gradations greater number habits Hence hybrids important 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 reproductive resemblance rudimentary seeds sexual selection slight South America stamens sterility structure struggle successive supposed tend theory tion variability variations varieties vary whilst whole wings young