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 viii
... ancient forms On the succession of the same types within the same areas 312-345 Summary of preceding and present chapters CHAPTER XI . GEOGRAPHICAL DISTRIBUTION . - Present distribution cannot be accounted for by differences in phy ...
... ancient forms On the succession of the same types within the same areas 312-345 Summary of preceding and present chapters CHAPTER XI . GEOGRAPHICAL DISTRIBUTION . - Present distribution cannot be accounted for by differences in phy ...
Página 18
... ancient records , more especially on the monuments of Egypt , much diversity in the breeds ; and that some of the breeds closely resemble , perhaps are identical with , those still existing . Even if this latter fact were found more ...
... ancient records , more especially on the monuments of Egypt , much diversity in the breeds ; and that some of the breeds closely resemble , perhaps are identical with , those still existing . Even if this latter fact were found more ...
Página 24
... ancient times by half - civi- lized man , as to be quite prolific under confinement . An argument , as it seems to me , of great weight , and applicable in several other cases , is , that the above- specified breeds , though agreeing ...
... ancient times by half - civi- lized man , as to be quite prolific under confinement . An argument , as it seems to me , of great weight , and applicable in several other cases , is , that the above- specified breeds , though agreeing ...
Página 34
... ancient Chinese encyclopædia . Ex- plicit rules are laid down by some of the Roman classical writers . From passages in Genesis , it is clear that the colour of domestic animals was at that early period attended to . Savages now ...
... ancient Chinese encyclopædia . Ex- plicit rules are laid down by some of the Roman classical writers . From passages in Genesis , it is clear that the colour of domestic animals was at that early period attended to . Savages now ...
Página 74
... ancient Indian ruins in the Southern United States , which must formerly have been cleared of trees , now display the same beautiful diversity and proportion of kinds as in the surrounding virgin forests . What a struggle between the ...
... ancient Indian ruins in the Southern United States , which must formerly have been cleared of trees , now display the same beautiful diversity and proportion of kinds as in the surrounding virgin forests . What a struggle between the ...
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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