On the Origin of Species by Means of Natural Selection: Or, The Preservation of Favored Races in the Struggle of LifeAppleton, 1864 - Всего страниц: 440 |
Результаты поиска по книге
Результаты 1 – 5 из 71
Стр. 11
... seeds that must be transported by certain birds , and which has flowers with separate sexes abso- lutely requiring the agency of certain insects to bring pol- len from one flower to the other , it is equally preposterous to account for ...
... seeds that must be transported by certain birds , and which has flowers with separate sexes abso- lutely requiring the agency of certain insects to bring pol- len from one flower to the other , it is equally preposterous to account for ...
Стр. 15
... seed ! In some few such cases it has been found out that very trifling changes , such as a little more or less water at some particular period of growth , will determine whether or not the plant sets a seed . I cannot here enter on the ...
... seed ! In some few such cases it has been found out that very trifling changes , such as a little more or less water at some particular period of growth , will determine whether or not the plant sets a seed . I cannot here enter on the ...
Стр. 16
... seed . These " sports " are extremely rare under nature , but far from rare under cultivation ; and in this case we see that the treatment of the parent has affected a bud or offset , and not the ovules or pollen . But it is the opinion ...
... seed . These " sports " are extremely rare under nature , but far from rare under cultivation ; and in this case we see that the treatment of the parent has affected a bud or offset , and not the ovules or pollen . But it is the opinion ...
Стр. 32
... several sorts , for instance a Ribston - pippin or Codlin - apple , could ever have proceeded from the seeds of the same tree . In- . numerable other examples could be given . The explana- tion 32 [ CHAP . L DOMESTIC PIGEONS .
... several sorts , for instance a Ribston - pippin or Codlin - apple , could ever have proceeded from the seeds of the same tree . In- . numerable other examples could be given . The explana- tion 32 [ CHAP . L DOMESTIC PIGEONS .
Стр. 36
... seed - raisers do not pick out the best plants , but merely go over their seed - beds , and pull up the " rogues , " as they call the plants that deviate from the proper standard . With animals this kind of selection is , in fact , also ...
... seed - raisers do not pick out the best plants , but merely go over their seed - beds , and pull up the " rogues , " as they call the plants that deviate from the proper standard . With animals this kind of selection is , in fact , also ...
Другие издания - Просмотреть все
The Origin of Species by Means of Natural Selection: Or, The ..., Том 1 Charles Darwin Полный просмотр - 1889 |
The Origin of Species by Means of Natural Selection: Or, the ..., Том 1 Charles Darwin Полный просмотр - 1898 |
Часто встречающиеся слова и выражения
accumulated adapted affinities allied species America amount ancient animals appear become bees believe birds breeds cause cells characters cirripedes climate closely allied colour continuous crossed crustaceans degree difficulty distinct species disuse divergence domestic 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 intermediate land larvæ less living look male mammals manner migration modification modified descendants natural selection naturalists nearly nest offspring organic organisation perfect pigeons pistil plants pollen present probably produced progenitor ranked reciprocal crosses remarked resemble rudimentary seeds seems sexual selection Silurian slight South America sterility structure struggle successive suppose swimbladder tend theory tion trees variability variation varieties vary whole widely
Популярные отрывки
Стр. 424 - In the distant future I see open fields for far more important researches. Psychology will be based on a new foundation, that of the necessary acquirement of each mental power and capacity by gradation. Light will be thrown on the origin of man and his history.
Стр. 63 - There is no exception to the rule that every organic being naturally increases at so high a rate, that, if not destroyed, the earth would soon be covered by the progeny of a single pair.
Стр. 79 - I may be allowed to personify the natural preservation or survival of the fittest, cares nothing for appearances, except in so far as they are useful to any being. She can act on every internal organ, on every shade of constitutional difference, on the whole machinery of life. Man selects only for his own good: Nature only for that of the being which she tends.
Стр. 70 - I counted thirtytwo little trees ; and one of them, with twenty-six rings of growth, had during many years tried to raise its head above the stems of the heath, and had failed. No wonder that, as soon as the land was enclosed, it became thickly clothed with vigorously growing young firs. Yet the heath was so extremely barren and so extensive that no one would ever have imagined that cattle would have so closely and effectually searched it for food. Here we see that cattle absolutely determine the...
Стр. 169 - If it could be demonstrated that any complex organ existed, which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down.
Стр. 63 - Hence as more individuals are produced than can possibly survive, there must in every case be a struggle for existence, either one individual with another of the same species, or with the individuals of distinct species, or with the physical conditions of life.
Стр. 167 - To suppose that the eye with all its inimitable contrivances for adjusting the focus to different distances, for admitting different amounts of light, and for the correction of spherical and chromatic aberration, could have been formed by natural selection, seems, I freely confess, absurd in the highest degree.
Стр. 378 - Nothing can be more hopeless than to attempt to explain this similarity of pattern in members of the same class, by utility or by the doctrine of final causes. The hopelessness of the attempt has been expressly admitted by Owen in his most interesting work on the 'Nature of Limbs.
Стр. 187 - Under changed conditions of life, it is at least possible that slight modifications of instinct might be profitable to a species; and if it can be shown that instincts do vary ever so little, then I can see no difficulty in natural selection preserving and continually accumulating variations of instinct to any extent that was profitable. It is thus, as I believe, that all the most complex and wonderful instincts have originated.
Стр. 165 - I can see no difficulty in a race of bears being rendered, by natural selection, more and more aquatic in their structure and habits, with larger and larger mouths, till a creature was produced as monstrous as a whale.