A Primer of Darwinism and Organic Evolution |
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Page 18
... evidence of the possibility of the little grape- like cluster at some time , how long ago no one can even guess , having originated by a variation from the usual sort of fern leaf , or frond as it is more properly called . Such ...
... evidence of the possibility of the little grape- like cluster at some time , how long ago no one can even guess , having originated by a variation from the usual sort of fern leaf , or frond as it is more properly called . Such ...
Page 25
... evidence which must give his conclusions the greatest weight . Each of the series I. , II . , III . , IV . , seems to have had its origin in the species which forms the lowest member of its column , i . e . , Series I. from the form ...
... evidence which must give his conclusions the greatest weight . Each of the series I. , II . , III . , IV . , seems to have had its origin in the species which forms the lowest member of its column , i . e . , Series I. from the form ...
Page 28
... evidence of the irresistible tendency of animals and plants to vary . How sudden and profound such variations may some- times be is shown by cases like that of certain brine - shrimps , to which I shall refer more fully in the coming ...
... evidence of the irresistible tendency of animals and plants to vary . How sudden and profound such variations may some- times be is shown by cases like that of certain brine - shrimps , to which I shall refer more fully in the coming ...
Page 42
... evidence has been accumulated tending to show that this process of variation under the influence of some pressure or stimu- lus arising from the environment , followed by inheritance of the new traits thus acquired , has gone on ...
... evidence has been accumulated tending to show that this process of variation under the influence of some pressure or stimu- lus arising from the environment , followed by inheritance of the new traits thus acquired , has gone on ...
Page 48
... Evidence in abundance of the generality of the occurrence of both acceleration and retardation as factors in species - making , has already been collected . For evidence to prove the fact of inheritance of acquired characteristics it ...
... Evidence in abundance of the generality of the occurrence of both acceleration and retardation as factors in species - making , has already been collected . For evidence to prove the fact of inheritance of acquired characteristics it ...
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A Primer of Darwinism and Organic Evolution Joseph Young Bergen,Fanny Dickerson Bergen No preview available - 2015 |
Common terms and phrases
abundant algæ America ammonites ancestors animal or plant animals animals and plants apes argillite axolotl become birds body brain breed carboniferous cause cell changes chapter color common condition continent Darwin Delaware Bay deposits development theory dicotyledons domestic earth eggs embryo eozoic Europe evidence example fact fauna feet fishes flint flowering plants foraminifera forms fossil genera genus geological ages gravel groups growth Haeckel horse human hundred Hyatt illustration implements individual insects instance islands kind known latter less life-history living lizards lower animals mals mammals mesozoic natural selection naturalists O. C. Marsh observations organic evolution Origin of Species period pollen present produced Professor quoted rabbits races regard region reptiles resemblance result salamander says seeds sexual shells shown silurian similar skull snails spores Steinheim striking structure sub-kingdom surface teeth tion toes trees variations varieties vegetable vertebrates Wallace wild species zoological
Popular passages
Page 226 - ... would it be too bold to imagine, that all warmblooded animals have arisen from one living filament, which THE GREAT FIRST CAUSE endued with animality, with the power of acquiring new parts, attended with new propensities, directed by irritations, sensations, volitions, and associations; and thus possessing the faculty of continuing to improve by its own inherent activity, and of delivering...
Page 229 - America, and in the geological relations of the present to the past inhabitants of the continent. These facts 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. On my return home it occurred to me (in 1837) that something might perhaps be made out on this question by patiently accumulating and reflecting on all sorts of facts which could possibly have any bearing on it. After five years I allowed myself to...
Page 58 - Even slow-breeding man has doubled in twenty-five years, and at this rate, in a few thousand years, there would literally not be standing room for his progeny. Linnaeus has calculated that if an annual plant produced only two seeds — and there is no plant so unproductive as this — and their seedlings next year produced two, and so on, then in twenty years there would be a million plants.
Page 58 - ... and during some season or occasional year, otherwise, on the principle of geometrical increase, its numbers would quickly become so inordinately great that no country could support the product.
Page 6 - The tawny lion, pawing to get free His hinder parts, then springs as broke from bonds, And rampant shakes his brinded mane...
Page 28 - On the evidence of palaeontology, the evolution of many existing forms of animal life from their predecessors is no longer an hypothesis, but an historical fact ; it is only the nature of the physiological factors to which that evolution is due which is still open to discussion.
Page 229 - On my return home, it occurred to me — in 1837 — that something might perhaps be made out on this question by patiently accumulating and reflecting on all sorts of facts which could possibly have any bearing on it. After five years' work I allowed myself to speculate on the subject, and drew up some short notes. These I enlarged in 1844 into a sketch of the conclusions which then seemed to me probable. From that period to the present day I have steadily pursued the same object. I hope that I...
Page 183 - ... Not being able to appreciate, or conceive, of the distinction between the psychical phenomena of a chimpanzee and of a Boschisman, or of an Aztec with arrested brain-growth, as being of a nature so essential as to preclude a comparison between them, or as being other than a difference of degree, I cannot shut my eyes to the significance of that all-pervading similitude of structure — every tooth, every bone, strictly homologous — which makes the determination of the difference between Homo...
Page 190 - Further towards the north are to be found men living absolutely in a state of nature, who neither cultivate the ground, nor live in huts ; who neither eat rice nor salt, and who do not associate with each other, but rove about some woods, like wild beasts.
Page 232 - The final cause, of this contest amongst the males seems to be, that the strongest and most active animal should propagate the species, which should thence become improved.