The Origin of Species by Means of Natural Selection: Or, The Preservation of Favoured Races in the Struggle for LifeJohn Murray, 1882 - Всего страниц: 458 |
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Стр. vii
... hybrids - Sterility various in degree , not universal , affected by close interbreeding , re- moved by domestication - Laws governing the sterility of hybrids --- Sterility not a special endowment , but incidental on other differences ...
... hybrids - Sterility various in degree , not universal , affected by close interbreeding , re- moved by domestication - Laws governing the sterility of hybrids --- Sterility not a special endowment , but incidental on other differences ...
Стр. xii
... hybrid moths . The discussion on the fertility of hybrids not having been ac- quired through natural selection condensed and modified . On the causes of sterility of hybrids , added to and corrected . Pyrgoma found in the chalk ...
... hybrid moths . The discussion on the fertility of hybrids not having been ac- quired through natural selection condensed and modified . On the causes of sterility of hybrids , added to and corrected . Pyrgoma found in the chalk ...
Стр. 7
... hybrids . When , on the one hand , we see domesticated animals and plants , though often weak and sickly , breeding freely under confinement ; and when , on the other hand , we see individuals , though taken young from a state of nature ...
... hybrids . When , on the one hand , we see domesticated animals and plants , though often weak and sickly , breeding freely under confinement ; and when , on the other hand , we see individuals , though taken young from a state of nature ...
Стр. 19
... hybrids or mongrels from between all the breeds of the pigeon are perfectly fertile , as I can state from my own obser- vations , purposely made , on the most distinct breeds . Now , hardly any cases have been ascertained with certainty ...
... hybrids or mongrels from between all the breeds of the pigeon are perfectly fertile , as I can state from my own obser- vations , purposely made , on the most distinct breeds . Now , hardly any cases have been ascertained with certainty ...
Стр. 32
... hybrids and of mongrels , and the sterility of hybrids ; but plants not propagated by seed are of little importance to us , for their endurance is only temporary . Over all these causes of Change , the accumulative action of Selection ...
... hybrids and of mongrels , and the sterility of hybrids ; but plants not propagated by seed are of little importance to us , for their endurance is only temporary . Over all these causes of Change , the accumulative action of Selection ...
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On the Origin of Species by Means of Natural Selection: Or The ..., Том 2 Charles Darwin Полный просмотр - 1888 |
Часто встречающиеся слова и выражения
adapted admit affinities allied species America analogous ancient appear beak become bees believe belonging birds breeds cause cells characters climate closely allied colour continuous crossed crustaceans degree developed difficulty distinct species doubt effects eggs embryo existing extinct extremely facts favourable fertilised fertility flowers formations formerly forms fossil Fritz Müller genera genus geological geological period Glacial period gradations greater number groups of species habits Hence hybrids important individuals inhabitants inherited insects instance instincts intercrossing intermediate kind lamellæ larvæ less living male mammals manner Marsupials migration modified descendants natural selection naturalists nearly nest occasionally oceanic islands offspring organisation organs parent peculiar perfect pigeon pistil pollen present preserved principle probably produced quadrupeds ranked reciprocal crosses remarked reproductive resemblance rudimentary seeds sexual selection slight South America stamens sterility structure struggle successive supposed tend theory tion variability variations varieties vary whilst whole wings young
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Стр. 64 - It may be said that natural selection is daily and hourly scrutinising, throughout the world, every variation, even the slightest; rejecting that which is bad, preserving and adding up all that is good; silently and insensibly working, whenever and wherever opportunity offers, at the improvement of each organic being in relation to its organic and inorganic conditions of life.
Стр. 48 - In these several senses, which pass into each other, I use for convenience' sake the general term of Struggle for Existence.
Стр. 63 - Nature's productions should be far 'truer' in character than man's productions; that they should be infinitely better adapted to the most complex conditions of life, and should plainly bear the stamp of far higher workmanship?
Стр. 61 - If such do occur, can we doubt (remembering that many more individuals are born than can possibly survive) that individuals having any advantage, however slight, over others, would have the best chance of surviving and of procreating their kind? On the other hand, we may feel sure that any variation in the least degree injurious would be rigidly destroyed.
Стр. 162 - If it could be proved that any part of the structure of any one species had been formed for the exclusive good of another species, it would annihilate my theory, for such could not have been produced through natural selection.
Стр. 48 - It is the doctrine of Malthus applied with manifold force to the whole animal and vegetable kingdoms ; for in this case there can be no artificial increase of food, and no prudential restraint from marriage.
Стр. 382 - What can be more curious than that the hand of a man, formed for grasping, that of a mole for digging, the leg of the horse, the paddle of the porpoise, and the wing of the bat, should all be constructed on the same pattern, and should include similar bones, in the same relative positions?
Стр. 146 - 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. 61 - Several writers have misapprehended or objected to the term Natural Selection, Some have even imagined that natural selection induces variability, whereas it' implies only the. preservation of such variations as arise and are beneficial to the being under its conditions of * life.
Стр. xvii - 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.