On the Origin of Species by Means of Natural Selection: Or, The Preservation of Favoured Races in the Struggle for Life"In considering the Origin of Species, it is quite conceivable that a naturalist, reflecting on the mutual affinities of organic beings, on their embryological relations, their geographical distribution, geological succession, and other such facts, might come to the conclusion that each species had not been independently created, but had descended, like varieties, from other species. Nevertheless, such a conclusion, even if well founded, would be unsatisfactory, until it could be shown how the innumerable species inhabiting this world have been modified, so as to acquire that perfection of structure and coadaptation which most justly excites our admiration. Naturalists continually refer to external conditions, such as climate, food, & c, as the only possible cause of variation. In one very limited sense, as we shall hereafter see, this may be true; but it is preposterous to attribute to mere external conditions, the structure, for instance, of the woodpecker, with its feet, tail, beak, and tongue, so admirably adapted to catch insects under the bark of trees. In the case of the misseltoe, which draws its nourishment from certain trees, which has seeds that must be transported by certain birds, and which has flowers with separate sexes absolutely requiring the agency of certain insects to bring pollen from one flower to the other, it is equally preposterous to account for the structure of this parasite, with its relations to several distinct organic beings, by the effects of external conditions, or of habit, or of the volition of the plant itself"--Introduction. (PsycINFO Database Record (c) 2012 APA, all rights reserved) |
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Page 22
... points of structure which are variable . The period at which the perfect plumage is acquired varies , as does the state of the down with which the nestling birds are clothed when hatched . The shape and size of the eggs vary . The ...
... points of structure which are variable . The period at which the perfect plumage is acquired varies , as does the state of the down with which the nestling birds are clothed when hatched . The shape and size of the eggs vary . The ...
Page 27
... points of structure with all the domestic breeds . Secondly , although an English carrier or short - faced tumbler differs immensely in cer- tain characters from the rock - pigeon , yet by comparing the several sub - breeds of these ...
... points of structure with all the domestic breeds . Secondly , although an English carrier or short - faced tumbler differs immensely in cer- tain characters from the rock - pigeon , yet by comparing the several sub - breeds of these ...
Page 33
... point do not differ at all in other points ; this is hardly ever , perhaps never , the case . The laws of correlation of growth , the importance of which should never be overlooked , will ensure some dif- ferences ; but , as a general ...
... point do not differ at all in other points ; this is hardly ever , perhaps never , the case . The laws of correlation of growth , the importance of which should never be overlooked , will ensure some dif- ferences ; but , as a general ...
Page 39
... points of the breed . Nor let it be thought that some great deviation of structure would be necessary to catch the fancier's eye : he perceives extremely small differences , and it is in human nature to value any novelty , however ...
... points of the breed . Nor let it be thought that some great deviation of structure would be necessary to catch the fancier's eye : he perceives extremely small differences , and it is in human nature to value any novelty , however ...
Page 40
... points of value of the new sub - breed are once fully acknowledged , the principle , as I have called it , of unconscious selection will always tend , -perhaps more at one period than at another , as the breed rises or falls in fashion ...
... points of value of the new sub - breed are once fully acknowledged , the principle , as I have called it , of unconscious selection will always tend , -perhaps more at one period than at another , as the breed rises or falls in fashion ...
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Common terms and phrases
adapted affinities allied species America analogous ancient animals become bees believe birds breeds cause cells chapter characters cirripedes climate closely allied colour continuous crossed crustaceans degree difficulty distinct species divergence domestic doubt embryo Europe existing exterminated extinct extremely facts favourable Fcap fertility flowers formations forms fossil Gärtner genera genus geological geological period Glacial period greater number groups of species habits Hence hermaphrodites History hybrids hybrids produced important individuals inhabitants inherited insects instance instincts intercrossing intermediate land larvæ less living male mammals manner migration modification modified descendants natural selection naturalists nearly nest offspring perfect pigeons plants pollen Portrait Post 8vo present principle probably produced progenitor racter ranked reciprocal crosses remarked resemble rudimentary organs Second Edition seeds sexual selection Silurian slight South America sterility structure struggle successive supposed theory Third Edition tion variability variations varieties vary Vols widely Woodcuts