On the Origin of Species by Means of Natural Selection: Or The Preservation of Favoured Races in the Struggle for LifeHumphrey Milford, Oxford University Press, 1923 - 454 páginas |
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Página 52
... species to be a slow one . And this certainly is the case , if varieties be looked at as incipient species ; for my tables clearly show as a general rule that , wherever many species of a genus have been formed , the species of that ...
... species to be a slow one . And this certainly is the case , if varieties be looked at as incipient species ; for my tables clearly show as a general rule that , wherever many species of a genus have been formed , the species of that ...
Página 53
... species greater than the average are now manufacturing , many of the species already manufactured still to a certain extent resemble varieties , for they differ from each other by a less than usual amount of difference . Moreover , the ...
... species greater than the average are now manufacturing , many of the species already manufactured still to a certain extent resemble varieties , for they differ from each other by a less than usual amount of difference . Moreover , the ...
Página 54
... species , but which he considers as so closely allied to other species as to be of doubtful value : these 63 reputed species range on an average over 6.9 of the provinces into which Mr. Watson has divided Great Britain . Now , in this ...
... species , but which he considers as so closely allied to other species as to be of doubtful value : these 63 reputed species range on an average over 6.9 of the provinces into which Mr. Watson has divided Great Britain . Now , in this ...
Página 57
... species , become ultimately con- verted into good and distinct species , which in most cases obviously differ from each other far more than do the varieties of the same species ? How do those groups of species , which constitute what ...
... species , become ultimately con- verted into good and distinct species , which in most cases obviously differ from each other far more than do the varieties of the same species ? How do those groups of species , which constitute what ...
Página 64
... species gradually getting rarer and rarer , and finally disappearing ; and the change of climate being conspicuous , we are tempted to attribute the whole effect to its direct action . But this is a false view we forget that each species ...
... species gradually getting rarer and rarer , and finally disappearing ; and the change of climate being conspicuous , we are tempted to attribute the whole effect to its direct action . But this is a false view we forget that each species ...
Otras ediciones - Ver todas
On the Origin of Species by Means of Natural Selection: or the Preservation ... Charles Darwin Vista previa limitada - 2023 |
Términos y frases comunes
accumulated adapted affinities allied species America amount analogous ancient appear Archipelago become bees believe birds breeds cause cells characters cirripedes climate closely allied colour common parent continuous crossed crustaceans degree difficulty distinct species divergence doubt embryo endemic Europe existing exterminated extinct extremely facts favourable fertility flowers formations forms fossil Gärtner genera genus geological geological period Glacial period gradations greater number groups of species habits Hence hermaphrodites hybrids hybrids produced important individuals inhabitants inherited insects instance instincts intercrossing land larvæ less living male mammals manner Marsupials migration modification modified descendants natural selection naturalists nearly nest oceanic islands offspring organisation perfect pigeons pistil plants pollen present principle probably produced progenitor ranked reciprocal crosses remarked resemble rock-pigeon rudimentary organs seeds sexual selection Silurian slight South America sterility structure struggle successive suppose swimbladder tend theory tion trees variability variation vary whole widely