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 49
... ranked as distinct species by many entomologists . Even Ireland has a few animals , now generally regarded as varieties , but which have been ranked as species by some zoologists . Several most experienced ornithologists consider our ...
... ranked as distinct species by many entomologists . Even Ireland has a few animals , now generally regarded as varieties , but which have been ranked as species by some zoologists . Several most experienced ornithologists consider our ...
Page 50
... ranked as varieties . Close investigation , in most cases , will bring naturalists to an agreement how to rank doubtful forms . Yet it must be confessed that it is in the best - known countries that we find the greatest number of forms ...
... ranked as varieties . Close investigation , in most cases , will bring naturalists to an agreement how to rank doubtful forms . Yet it must be confessed that it is in the best - known countries that we find the greatest number of forms ...
Page 56
... suffices to raise one or both to the rank of species . Hence the amount of difference is one very important criterion in settling whether two forms should be ranked as species or varieties . Now Fries. 56 CHAP . II . SPECIES OF LARGE ...
... suffices to raise one or both to the rank of species . Hence the amount of difference is one very important criterion in settling whether two forms should be ranked as species or varieties . Now Fries. 56 CHAP . II . SPECIES OF LARGE ...
Page 57
... ranked as species or varieties . Now Fries has remarked in regard to plants , and Westwood in regard to insects , that in large genera the amount of difference between the species is often exceedingly small . I have endeavoured to test ...
... ranked as species or varieties . Now Fries has remarked in regard to plants , and Westwood in regard to insects , that in large genera the amount of difference between the species is often exceedingly small . I have endeavoured to test ...
Page 58
... ranked as species , but which he considers as so closely allied to other species as to be of doubtful value : these 63 reputed species range on an average over 6.9 of the provinces into which Mr. Watson has divided Great Britain . Now ...
... ranked as species , but which he considers as so closely allied to other species as to be of doubtful value : these 63 reputed species range on an average over 6.9 of the provinces into which Mr. Watson has divided Great Britain . Now ...
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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