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 |
Dentro del libro
Resultados 6-10 de 48
Página 52
... remarked in regard to plants , and Westwood in regard to insects , that in large genera the amount of difference between the species is often exceedingly small . I have endeavoured to test this numerically by averages , and , as far as ...
... remarked in regard to plants , and Westwood in regard to insects , that in large genera the amount of difference between the species is often exceedingly small . I have endeavoured to test this numerically by averages , and , as far as ...
Página 53
... remarked , little groups of species are generally clustered like satellites around certain other species . And what are varieties but groups of forms , unequally related to each other , and clustered round certain forms - that is ...
... remarked , little groups of species are generally clustered like satellites around certain other species . And what are varieties but groups of forms , unequally related to each other , and clustered round certain forms - that is ...
Página 104
... remarked in his great and admirable work , that floras gain by naturalisation , proportionally with the number of the native genera and species , far more in new genera than in new species . To give a single instance in the last edition ...
... remarked in his great and admirable work , that floras gain by naturalisation , proportionally with the number of the native genera and species , far more in new genera than in new species . To give a single instance in the last edition ...
Página 105
... remarked , our carnivorous , ruminant , and rodent mammals , could successfully compete with these well - pronounced orders . In the Australian mammals , we see the process of diversification in an early and incomplete stage of ...
... remarked , our carnivorous , ruminant , and rodent mammals , could successfully compete with these well - pronounced orders . In the Australian mammals , we see the process of diversification in an early and incomplete stage of ...
Página 116
... remarked , leads to divergence of character and to much extinction of the less improved and intermediate forms of life . On these principles , I believe , the nature of the affinities of all organic beings may be explained . It is a ...
... remarked , leads to divergence of character and to much extinction of the less improved and intermediate forms of life . On these principles , I believe , the nature of the affinities of all organic beings may be explained . It is a ...
Otras ediciones - Ver todas
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