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 4
... see how Natural Selection almost in- evitably causes much Extinction of the less improved forms of life , and leads to what I have called Divergence of Character . In the next chapter I shall discuss 4 ON THE ORIGIN OF SPECIES.
... see how Natural Selection almost in- evitably causes much Extinction of the less improved forms of life , and leads to what I have called Divergence of Character . In the next chapter I shall discuss 4 ON THE ORIGIN OF SPECIES.
Página 6
... extinct species , in the same manner as the acknowledged varieties of any one species are the descendants of that species . Furthermore , I am convinced that Natural Selection has been the main but not exclusive means of modification ...
... extinct species , in the same manner as the acknowledged varieties of any one species are the descendants of that species . Furthermore , I am convinced that Natural Selection has been the main but not exclusive means of modification ...
Página 22
... extinct in the wild state . But birds breeding on preci- pices , and good fliers , are unlikely to be exterminated ; and the common rock - pigeon , which has the same habits with the domestic breeds , has not been exter- minated even on ...
... extinct in the wild state . But birds breeding on preci- pices , and good fliers , are unlikely to be exterminated ; and the common rock - pigeon , which has the same habits with the domestic breeds , has not been exter- minated even on ...
Página 23
... extinct or unknown . So many strange con- tingencies seem to me improbable in the highest degree . Some facts in regard to the colouring of pigeons well deserve consideration . The rock - pigeon is of a slaty- blue , and has a white ...
... extinct or unknown . So many strange con- tingencies seem to me improbable in the highest degree . Some facts in regard to the colouring of pigeons well deserve consideration . The rock - pigeon is of a slaty- blue , and has a white ...
Página 48
... extinct , or they may endure as varieties for very long periods , as has been shown to be the case by Mr. Wollaston with the varieties of certain fossil land - shells in Madeira . If a variety were to flourish so as to exceed in numbers ...
... extinct , or they may endure as varieties for very long periods , as has been shown to be the case by Mr. Wollaston with the varieties of certain fossil land - shells in Madeira . If a variety were to flourish so as to exceed in numbers ...
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