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 3
... slight variations . I will then pass on to the variability of species in a state of nature ; but I shall , unfortunately , be compelled to treat this subject far too briefly , as it can be treated properly only by giving long catalogues ...
... slight variations . I will then pass on to the variability of species in a state of nature ; but I shall , unfortunately , be compelled to treat this subject far too briefly , as it can be treated properly only by giving long catalogues ...
Página 6
... slight changes , such as size from the amount of food , colour from the nature of the food , thickness of the skin and hair from climate , & c . Each of the endless variations which we see in the plumage of our fowls must have had some ...
... slight changes , such as size from the amount of food , colour from the nature of the food , thickness of the skin and hair from climate , & c . Each of the endless variations which we see in the plumage of our fowls must have had some ...
Página 7
... slight changes in the surrounding conditions . Nothing is more easy than to tame an animal , and few things more difficult than to get it to breed freely under confinement , even when the male and female unite . How many animals there ...
... slight changes in the surrounding conditions . Nothing is more easy than to tame an animal , and few things more difficult than to get it to breed freely under confinement , even when the male and female unite . How many animals there ...
Página 9
... slight degree from that of the parental type . Any variation which is not inherited is unimportant for us . But the number and diversity of inheritable deviations of structure , both those of slight and those of considerable ...
... slight degree from that of the parental type . Any variation which is not inherited is unimportant for us . But the number and diversity of inheritable deviations of structure , both those of slight and those of considerable ...
Página 11
... slight deviations in their structure , in such case , I grant that we could deduce nothing from domestic varieties in regard to species . But there is not a shadow of evidence in favour of this view : to assert that we could not breed ...
... slight deviations in their structure , in such case , I grant that we could deduce nothing from domestic varieties in regard to species . But there is not a shadow of evidence in favour of this view : to assert that we could not breed ...
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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