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 46
... Hence , number is of the highest importance for success . On this principle Marshall formerly remarked , with respect to the sheep of parts of Yorkshire , " as they generally belong to poor people , and are mostly in small lots , they ...
... Hence , number is of the highest importance for success . On this principle Marshall formerly remarked , with respect to the sheep of parts of Yorkshire , " as they generally belong to poor people , and are mostly in small lots , they ...
Página 57
... Hence , in determining whether a form should be ranked as a species or a variety , the opinion of natural- ists having sound judgment and wide experience seems the only guide to follow . We must , however , in many cases , decide by a ...
... Hence , in determining whether a form should be ranked as a species or a variety , the opinion of natural- ists having sound judgment and wide experience seems the only guide to follow . We must , however , in many cases , decide by a ...
Página 65
... Hence I look at individual differences , though of small interest to the systematist , as of the highest im- portance for us , as being the first steps towards such slight varieties as are barely thought worth recording in works on ...
... Hence I look at individual differences , though of small interest to the systematist , as of the highest im- portance for us , as being the first steps towards such slight varieties as are barely thought worth recording in works on ...
Página 67
... Hence it is the most flourishing , or , as they may be called , the dominant species , -those which range widely , are the most diffused in their own coun- try , and are the most numerous in individuals , —which oftenest produce well ...
... Hence it is the most flourishing , or , as they may be called , the dominant species , -those which range widely , are the most diffused in their own coun- try , and are the most numerous in individuals , —which oftenest produce well ...
Página 69
... hence we might expect that the circumstances would generally be still favourable to variation . On the other hand , if we look at each species as a special act of creation , there is no apparent reason why more varieties should occur in ...
... hence we might expect that the circumstances would generally be still favourable to variation . On the other hand , if we look at each species as a special act of creation , there is no apparent reason why more varieties should occur in ...
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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