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 1-5 de 100
Página 26
... groups of birds , in nature . One circumstance has struck me much ; namely , that all the breeders of the various domestic animals and the cultivators of plants , with whom I have ever conversed , or whose treatises I have read , are ...
... groups of birds , in nature . One circumstance has struck me much ; namely , that all the breeders of the various domestic animals and the cultivators of plants , with whom I have ever conversed , or whose treatises I have read , are ...
Página 47
... group of organisms quite unknown to him , he is at first much perplexed to determine what differences to consider as ... groups and in other countries , by which to correct his first impres- sions . As he extends the range of his ...
... group of organisms quite unknown to him , he is at first much perplexed to determine what differences to consider as ... groups and in other countries , by which to correct his first impres- sions . As he extends the range of his ...
Página 53
... groups . As Fries has well 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 ...
... groups . As Fries has well 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 ...
Página 55
... groups subordinate to groups . CHAPTER III STRUGGLE FOR EXISTENCE Bears on natural selection - VARIATION UNDER NATURE 55.
... groups subordinate to groups . CHAPTER III STRUGGLE FOR EXISTENCE Bears on natural selection - VARIATION UNDER NATURE 55.
Página 57
... groups of species , which constitute what are called distinct genera , and which differ from each other more than do the species of the same genus , arise ? All these results , as we shall more fully see in the next chapter , follow ...
... groups of species , which constitute what are called distinct genera , and which differ from each other more than do the species of the same genus , arise ? All these results , as we shall more fully see in the next chapter , follow ...
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