On the Origin of Species by Means of Natural Selection: Or, The Preservation of Favoured Races in the Struggle for LifeEaston Press, 1976 - 470 páginas |
Dentro del libro
Resultados 1-3 de 39
Página 90
... interval , variety a1 is supposed in the diagram to have produced variety a2 , which will , owing to the principle of ... intervals long enough to allow the accumulation of a considerable amount of divergent variation . As all the ...
... interval , variety a1 is supposed in the diagram to have produced variety a2 , which will , owing to the principle of ... intervals long enough to allow the accumulation of a considerable amount of divergent variation . As all the ...
Página 311
... intervals between existing genera , families , and orders , is certainly true ; but as this statement has often been ignored or even denied , it may be well to make some remarks on this subject , and to give some instances . If we ...
... intervals between existing genera , families , and orders , is certainly true ; but as this statement has often been ignored or even denied , it may be well to make some remarks on this subject , and to give some instances . If we ...
Página 443
... intervals between the successive stages as having been of vast duration . But we shall be able to gauge with some security the duration of these intervals by a comparison , of the preceding and succeeding organic forms . We must be ...
... intervals between the successive stages as having been of vast duration . But we shall be able to gauge with some security the duration of these intervals by a comparison , of the preceding and succeeding organic forms . We must be ...
Contenido
VARIATION UNDER NATURE | 30 |
STRUGGLE FOR EXISTENCE | 45 |
NATURAL SELECTION | 59 |
Derechos de autor | |
Otras 13 secciones no mostradas
Otras ediciones - Ver todas
Términos y frases comunes
accumulated adapted admit affinities allied species America ancient appear beak become bees believe belonging birds breeds cause cells characters climate closely allied colour common progenitor continuous crossed crustaceans degree developed difficulty distinct species divergence doubt effects eggs embryo existing exterminated extinct extremely facts favourable fertilised fertility flowers formation forms fossil Fritz Müller genera genus geological geological period gradations greater number groups of species habits Hence hybrids hybrids produced important increase 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 offspring organisation organs Origin of Species parent peculiar perfect pigeons pistil plants pollen present preserved principle probably produced quadrupeds ranked reciprocal crosses remarked resemblance rudimentary seeds slight South America stamens sterility structure struggle successive supposed swimbladder theory variability variations varieties vary whilst whole wings young