The Darwinian Theory of the Transmutation of Species |
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Page 4
... fertile crosses without limit , but that the species dog and the species fox can not . Thus in fact Mr Darwin here confirms , as in other pas- sages , the point he denies . Take again this statement . I look at varieties which are in ...
... fertile crosses without limit , but that the species dog and the species fox can not . Thus in fact Mr Darwin here confirms , as in other pas- sages , the point he denies . Take again this statement . I look at varieties which are in ...
Page 15
... fertile mongrels , but not hybrids . All the races of dogs are fertile with one another , and their fecundity continues in their descendants , whatever the mixture may have been . Yet these mongrels continue to be dogs ; no new animal ...
... fertile mongrels , but not hybrids . All the races of dogs are fertile with one another , and their fecundity continues in their descendants , whatever the mixture may have been . Yet these mongrels continue to be dogs ; no new animal ...
Page 27
... fertile ' ( 27 ) . I do not know of any thoroughly well - authenticated case of a perfectly fertile hybrid animal ' ( 275 ) . Mr Hewitt , who has had great experience in hybridizing gallinaceous birds , informs me that the early death ...
... fertile ' ( 27 ) . I do not know of any thoroughly well - authenticated case of a perfectly fertile hybrid animal ' ( 275 ) . Mr Hewitt , who has had great experience in hybridizing gallinaceous birds , informs me that the early death ...
Page 32
... fertile males and females of the same community flourished , and transmitted to their fertile offspring a tendency to produce sterile members having the same modification . And , I believe , that this process has been repeated , until ...
... fertile males and females of the same community flourished , and transmitted to their fertile offspring a tendency to produce sterile members having the same modification . And , I believe , that this process has been repeated , until ...
Page 33
... fertile together , ' and analogy makes me greatly doubt , whether the several aboriginal species would , at first , have freely bred together , and have produced quite fertile hybrids ( 266 ) . First it is This passage involves the ...
... fertile together , ' and analogy makes me greatly doubt , whether the several aboriginal species would , at first , have freely bred together , and have produced quite fertile hybrids ( 266 ) . First it is This passage involves the ...
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advance ages algæ amongst ancient appear beauty bees believe birds blood bones character contrivances creation creatures Cuvier Darwin Darwin's Theory descended difficulty distinct earth effected Eocene existence explain exterminated fact favoured female fertile fishes formation forms genera geology germ giraffe gorilla habits hive-bee horse human hybrid imagination improvement insects instance instinct intellect Lamarck learned limbs living Lucretius Lyell male means ment metaphor millions modification mutation Natural Selection naturalists never object observed organic Origin of Species passage perfect physiologists plants principle produced Professor progenitor proof quadrupeds race reason red clover reptiles respiration result 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 words
Popular passages
Page 20 - 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.
Page 70 - 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.
Page 20 - 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.
Page 348 - 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.
Page 7 - 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.
Page 232 - the recognition of an ideal Exemplar for the Vertebrated Animals proves that the Knowledge of such a being as Man must have existed before Man appeared. For the Divine mind which planned the Archetype also foreknew all its modifications. The Archetypal idea was manifested in the flesh, under divers modifications, upon this planet, long prior to the existence of those animal species that actually exemplify it.
Page 61 - 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.
Page 1 - 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.
Page 136 - 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.
Page 170 - Consequently, if my theory be true, it is indisputable that before the lowest Silurian stratum was deposited, long periods elapsed, as long as, or probably far longer than, the whole interval from the Silurian age to the present day; and that during these vast, yet quite unknown, periods of time, the world swarmed with living creatures.