On the Origin of Species by Means of Natural Selection: Or, The Preservation of Favoured Races in the Struggle for LifeJ. Murray, 1860 - 502 páginas "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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Página 11
... seen , and will be hereafter briefly mentioned . I will here only allude to what may be called correlation of growth . Any change in the embryo or larva will almost certainly entail changes in the mature animal . In monstrosities , the ...
... seen , and will be hereafter briefly mentioned . I will here only allude to what may be called correlation of growth . Any change in the embryo or larva will almost certainly entail changes in the mature animal . In monstrosities , the ...
Página 12
... seen laws of variation is infinitely complex and diversified . It is well worth while carefully to study the several treatises published on some of our old cultivated plants , as on the hyacinth , potato , even the dahlia , & c .; and ...
... seen laws of variation is infinitely complex and diversified . It is well worth while carefully to study the several treatises published on some of our old cultivated plants , as on the hyacinth , potato , even the dahlia , & c .; and ...
Página 35
... seen , as I am informed by him , any native dog in Spain like our pointer . By a similar process of selection , and by careful train- ing , the whole body of English racehorses have come to surpass in fleetness and size the parent Arab ...
... seen , as I am informed by him , any native dog in Spain like our pointer . By a similar process of selection , and by careful train- ing , the whole body of English racehorses have come to surpass in fleetness and size the parent Arab ...
Página 37
... seen great surprise expressed in horticultural works at the wonderful skill of gardeners , in having produced such splendid results from such poor materials ; but the art , I cannot doubt , has been simple , and , as far as the final ...
... seen great surprise expressed in horticultural works at the wonderful skill of gardeners , in having produced such splendid results from such poor materials ; but the art , I cannot doubt , has been simple , and , as far as the final ...
Página 41
... seen it gravely remarked , that it was most fortunate that the straw- berry began to vary just when gardeners began to attend closely to this plant . No doubt the strawberry had always varied since it was cultivated , but the slight ...
... seen it gravely remarked , that it was most fortunate that the straw- berry began to vary just when gardeners began to attend closely to this plant . No doubt the strawberry had always varied since it was cultivated , but the slight ...
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Términos y frases comunes
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