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 74
... become extinct . We may conclude , from what we have seen of the intimate and complex manner in which the inhabitants of each country are bound to- gether , that any change in the numerical proportions of some of the inhabitants ...
... become extinct . We may conclude , from what we have seen of the intimate and complex manner in which the inhabitants of each country are bound to- gether , that any change in the numerical proportions of some of the inhabitants ...
Página 79
... shell being known to vary like every other structure . Sexual Selection . -Inasmuch as peculiarities often appear under domestication in one sex and become hereditarily attached to that sex , the same fact prob- NATURAL SELECTION 79.
... shell being known to vary like every other structure . Sexual Selection . -Inasmuch as peculiarities often appear under domestication in one sex and become hereditarily attached to that sex , the same fact prob- NATURAL SELECTION 79.
Página 85
... become more or less impotent ; now if we suppose this to occur in ever so slight a degree under nature , then as pollen is already carried regularly from flower to flower , and as a more complete separa- tion of the sexes of our plant ...
... become more or less impotent ; now if we suppose this to occur in ever so slight a degree under nature , then as pollen is already carried regularly from flower to flower , and as a more complete separa- tion of the sexes of our plant ...
Página 86
... become rare in any country , it might be a great advantage to the red clover to have a shorter or more deeply divided tube to its corolla , so that the hive - bee could visit its flowers . Thus I can understand how a flower and a bee ...
... become rare in any country , it might be a great advantage to the red clover to have a shorter or more deeply divided tube to its corolla , so that the hive - bee could visit its flowers . Thus I can understand how a flower and a bee ...
Página 92
... becomes very small . From these several considerations and from the many special facts which I have collected , but which I am not here able to give , I am strongly inclined to suspect that , both in ... become 92 ON THE ORIGIN OF SPECIES.
... becomes very small . From these several considerations and from the many special facts which I have collected , but which I am not here able to give , I am strongly inclined to suspect that , both in ... become 92 ON THE ORIGIN OF 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