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 vi
... 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 106-132 CHAPTER VI . DIFFICULTIES OF THE THEORY ...
... 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 106-132 CHAPTER VI . DIFFICULTIES OF THE THEORY ...
Página vii
... Characters of small functional importance , the most constant - Supposed incom- petence of natural selection to account for the incipient stages of useful structures - Causes which interfere with the acquisition through natural ...
... Characters of small functional importance , the most constant - Supposed incom- petence of natural selection to account for the incipient stages of useful structures - Causes which interfere with the acquisition through natural ...
Página xv
... characters alone . After remarking that negroes and mulattoes enjoy an immunity from certain tropical diseases , he observes , firstly , that all animals tend to vary in some degree , and , secondly , that agriculturists improve their ...
... characters alone . After remarking that negroes and mulattoes enjoy an immunity from certain tropical diseases , he observes , firstly , that all animals tend to vary in some degree , and , secondly , that agriculturists improve their ...
Página xvi
... characters ; " but farther on ( p . 18 ) he adds , " except the original types or ancestors of the genus . " In 1843-44 Professor Ha'deman ( Boston Journal of Nat . Hist . U. States , ' vol . iv . p . 468 ) has ably given the arguments ...
... characters ; " but farther on ( p . 18 ) he adds , " except the original types or ancestors of the genus . " In 1843-44 Professor Ha'deman ( Boston Journal of Nat . Hist . U. States , ' vol . iv . p . 468 ) has ably given the arguments ...
Página 10
... character whatever as the rule , and non - inheritance as the anomaly . The laws governing inheritance are for the ... characters to its grandfather or grandmother or more remote ances- tor ; why a peculiarity is often transmitted from ...
... character whatever as the rule , and non - inheritance as the anomaly . The laws governing inheritance are for the ... characters to its grandfather or grandmother or more remote ances- tor ; why a peculiarity is often transmitted from ...
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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