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
... perfect - The law of Unity of Type and of the Conditions of Existence embraced by the theory of Natu- ral Selection . • . 207 CHAPTER VII . MISCELLANEOUS OBJECTIONS TO THE THEORY OF NATURAL SELECTION . Longevity - Modifications not ...
... perfect - The law of Unity of Type and of the Conditions of Existence embraced by the theory of Natu- ral Selection . • . 207 CHAPTER VII . MISCELLANEOUS OBJECTIONS TO THE THEORY OF NATURAL SELECTION . Longevity - Modifications not ...
Página xiv
... perfect gradation of forms in certain groups , and by the analogy of domestic produc- tions . With respect to the means of modification , he attributed something to the direct action of the physical conditions of life , something to the ...
... perfect gradation of forms in certain groups , and by the analogy of domestic produc- tions . With respect to the means of modification , he attributed something to the direct action of the physical conditions of life , something to the ...
Página 17
... perfect reversion had ensued . It would be neces- sary , in order to prevent the effects of intercrossing , that only a single variety should have been turned . loose in its new home . Nevertheless , as our varieties certainly do ...
... perfect reversion had ensued . It would be neces- sary , in order to prevent the effects of intercrossing , that only a single variety should have been turned . loose in its new home . Nevertheless , as our varieties certainly do ...
Página 18
... perfect fertility of varieties when crossed , -a subject hereafter to be discussed ) , domestic races of the same species differ from each other in the same manner as do the closely- allied species of the same genus in a state of nature ...
... perfect fertility of varieties when crossed , -a subject hereafter to be discussed ) , domestic races of the same species differ from each other in the same manner as do the closely- allied species of the same genus in a state of nature ...
Página 25
... perfect plumage is acquired varies , as does the state of the down with which the nestling birds are clothed when hatched . The shape and size of the eggs vary . The manner of flight , and in some breeds the voice and disposition ...
... perfect plumage is acquired varies , as does the state of the down with which the nestling birds are clothed when hatched . The shape and size of the eggs vary . The manner of flight , and in some breeds the voice and disposition ...
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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