The Darwinian Theory of the Transmutation of SpeciesJ. Nisbet, 1867 - Всего страниц: 386 |
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Стр. 23
... difficulty which he affirms there is in determining correctly the species of several plants , ' there are genera in which the species present an inordinate amount of variation ; and hardly two naturalists can agree which forms to rank ...
... difficulty which he affirms there is in determining correctly the species of several plants , ' there are genera in which the species present an inordinate amount of variation ; and hardly two naturalists can agree which forms to rank ...
Стр. 24
... difficulty by boldly affirming that the subject itself is altogether ideal , and therefore may be dismissed as imaginary ? By this mode of argument we might clear the stage of many hard questions in physics , and many disputes in ...
... difficulty by boldly affirming that the subject itself is altogether ideal , and therefore may be dismissed as imaginary ? By this mode of argument we might clear the stage of many hard questions in physics , and many disputes in ...
Стр. 28
... difficulties , created by his own theory , we must de- cline to accept his exegesis of the mysteries of nature . ― That he himself has but a faint confidence in his own exegesis , we may gather from the following words : ' It must be ...
... difficulties , created by his own theory , we must de- cline to accept his exegesis of the mysteries of nature . ― That he himself has but a faint confidence in his own exegesis , we may gather from the following words : ' It must be ...
Стр. 34
... difficulty , but with a hybrid progeny when ' at last produced , ' fertile . We are told that hybrids never have been raised between species ranked by systematists in distinct families ; and a multitude of cases could be given of very ...
... difficulty , but with a hybrid progeny when ' at last produced , ' fertile . We are told that hybrids never have been raised between species ranked by systematists in distinct families ; and a multitude of cases could be given of very ...
Стр. 41
... have been incom- parably great : but assuredly , IF THIS THEORY BE TRUE , such have lived upon earth ' ( 305 ) . ' I see no difficulty , under < changing conditions of life , in Natural Selection accumulat- NATURAL SELECTION . 41.
... have been incom- parably great : but assuredly , IF THIS THEORY BE TRUE , such have lived upon earth ' ( 305 ) . ' I see no difficulty , under < changing conditions of life , in Natural Selection accumulat- NATURAL SELECTION . 41.
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Часто встречающиеся слова и выражения
advance ages algæ amongst ancient antecedent appear beauty bees believe birds blood bones character contrivances creation creatures crustacean Cuvier Darwin Darwin's Theory descendants distinct earth effected elephant Eocene existence exterminated fact favoured female fishes foot formation genera geology giraffe gorilla habits heart horse human hybrid improvement insects instance instinct intellect Lamarck learned limbs living lower Lyell male means ment metaphor millions modification mutation Natural Selection naturalists negative evidence never object observed organic Origin of Species passage perfect physiologists plants prehensile principle produced Professor progenitor proof quadrupeds race racter red clover reptiles rocks says seems sequence of events Silurian soil spore sterility structure struggle suppose tail tapir Tertiary Theory of Transmutation things tion transformation TRANSMUTATION OF SPECIES Transmutationists Trémaux Trilobite variations varieties vertebral column vertebrata vertebrated animals whale whole wings words
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Стр. 7 - And God made the beast of the earth after his kind, and cattle after their kind, and every thing that creepeth upon the earth after his kind: and God saw that it was good.
Стр. 52 - 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. 7 - And God said, Let the earth bring forth grass, the herb yielding seed and the fruit tree yielding fruit after his kind, whose seed is in itself, upon the earth: and it was so. And the earth brought forth grass, and herb yielding seed after his kind, and the tree yielding fruit, whose seed was in itself, after his kind: and God saw that it was good.
Стр. 27 - So again it is difficult to avoid personifying the word Nature ; but I mean by Nature, only the aggregate action and product of many natural laws, and by laws the sequence of events as ascertained by us.
Стр. xiii - In short, we shall have to treat species in the same manner as those naturalists treat genera, who admit that genera are merely artificial combinations made for convenience. This may not be a cheering prospect ; but we shall at least be freed from the vain search for the undiscovered and undiscoverable essence of the term species.
Стр. 113 - 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.
Стр. 43 - The similar framework of bones in the hand of a man, wing of a bat, fin of the porpoise, and leg of the horse, — the same number of vertebrae forming the neck of the giraffe and of the elephant, — and innumerable other such facts, at once explain themselves on the theory of descent with slow and slight successive modifications.
Стр. xi - These facts, as will be seen in the latter chapters of this volume, seemed to throw some light on the origin of species — that mystery of mysteries, as it has been called by one of our greatest philosophers.
Стр. 221 - There is grandeur in this view of life, with its several powers, having been originally breathed by the Creator into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being evolved.
Стр. 26 - Slow though the process of selection may be, if feeble man can do much by his powers of artificial selection, I can see no limit to the amount of change, to the beauty and infinite complexity of the coadaptations between all organic beings, one with another and with their physical conditions of life, which may be effected in the long course of time by nature's power of selection.