The Foundations of the Origin of Species: Two Essays Written in 1842 and 1844University Press, 1909 - Всего страниц: 263 |
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Стр. 2
... parent transmits its peculiarities , therefore if varieties allowed freely to cross , except by the chance of two characterized by same peculiarity happening to marry , such varieties will be constantly demolished " . All bisexual ...
... parent transmits its peculiarities , therefore if varieties allowed freely to cross , except by the chance of two characterized by same peculiarity happening to marry , such varieties will be constantly demolished " . All bisexual ...
Стр. 3
... parent form - analogue of vis medicatrix2 . But if man selects , then new races rapidly formed , of late years systematically followed , -in most ancient times often practically followed3 . By such selection make race - horse , dray ...
... parent form - analogue of vis medicatrix2 . But if man selects , then new races rapidly formed , of late years systematically followed , -in most ancient times often practically followed3 . By such selection make race - horse , dray ...
Стр. 8
... parent ( ? ) fish deposits its egg in infinitesimally different circumstances , as in rather shallower or deeper water & c . , it will then ( ? ) tell . Let hares increase very slowly from change of climate affecting peculiar plants ...
... parent ( ? ) fish deposits its egg in infinitesimally different circumstances , as in rather shallower or deeper water & c . , it will then ( ? ) tell . Let hares increase very slowly from change of climate affecting peculiar plants ...
Стр. 15
... parents exposed for some generations to new conditions1 , and we now find that many animals when exposed for first time ... parent breeds and inter se for some generations . This is Koelreuter's belief . These facts throw light on each ...
... parents exposed for some generations to new conditions1 , and we now find that many animals when exposed for first time ... parent breeds and inter se for some generations . This is Koelreuter's belief . These facts throw light on each ...
Стр. 16
... parents , the difficulty of imagining intermediate forms of structure not sufficient to make one at once reject the theory . 1 This may be interpreted " The general structure of a bat is the same as that of non - flying mammals . " 2 ...
... parents , the difficulty of imagining intermediate forms of structure not sufficient to make one at once reject the theory . 1 This may be interpreted " The general structure of a bat is the same as that of non - flying mammals . " 2 ...
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abortive abortive organs acquired adapted admit affinity allied Alpine America analogous appear Archipelago become believe birds breed cattle cause changes chapter characters climate common descent continent corresponding crossing Darwin degree descended different species distinct distribution dogs domestic animals domestic races doubt effect embryo Europe existing external conditions extinct facts Falkland Islands favourable fertile floras forms fossil full-grown Galapagos Galapagos Archipelago genera genus geological germinal vesicle groups habits hereditary hybrids individuals inhabitants inherited instance instincts intermediate islands land larvæ less living main divisions mammæ mammifers Marsupial mature means mountains naturalists Note in original occasionally occurs offspring Origin of Species parent parent-stock passage peculiar period plants present Essay preserved probably produced quadrupeds remarked reproductive resemble Rodents seeds selection sheep similar slight stamens sterility structure suppose tend tendency terrestrial terrestrial animals theory Tierra del Fuego tion unity of type variation varieties vary whilst wild young
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Стр. 50 - There is grandeur in this view of life, with its several powers, having been originally breathed by the Creator into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being evolved.
Стр. xiv - Here then I had at last got a theory by which to work; but I was so anxious to avoid prejudice, that I determined not for some time to write even the briefest sketch of it. "In June 1842 I first allowed myself the satisfaction of writing a very brief abstract of my theory in pencil in 35 pages; and this was enlarged during the summer of 1844 into one of 230 pages which I had fairly copied out and still possess.
Стр. xiii - I happened to read for amusement ' Malthus on Population, and being well prepared to appreciate the struggle for existence which everywhere goes on from long-continued observation of the habits of animals and plants, it at once struck me that under these circumstances • favourable variations would tend to be preserved, and unfavourable ones to be destroyed. The result of this would be the formation of a new species. Here, then, I had at last got a theory by which to work...
Стр. xii - In July opened first note-book on Transmutation of Species. Had been greatly struck from about the month of previous March on character of South American fossils, and species on Galapagos Archipelago. These facts (especially latter), origin of all my views...
Стр. 250 - In the distant future I see open fields for far more important researches. Psychology will be based on a new foundation, that of the necessary acquirement of each mental power and capacity by gradation. Light will be thrown on the origin of man and his history.
Стр. x - During the voyage of the Beagle I had been deeply impressed by discovering in the Pampean formation great fossil animals covered with armour like that on the existing armadillos; secondly, by the manner in which closely allied animals replace one another in proceeding southwards...
Стр. x - It was evident that such facts as these, as well as many others, could only be explained on the supposition that species gradually become modified ; and the subject haunted me.
Стр. xiii - ... occasionally flitted across my mind. On my return home in the autumn of 1836, I immediately began to prepare my journal for publication, and then saw how many facts indicated the common descent of species, so that in July, 1837, I opened a note-book to record any facts which might bear on the question. But I did not become convinced that species were mutable until. I think, two or three years had elapsed.
Стр. 85 - In the majority of cases it is most difficult to imagine where the checks fall, though generally, no doubt, on the seeds, eggs and young ; but when we remember how impossible, even in mankind (so much better known than any other animal), it is to infer from repeated casual observations what the average duration of life is, or to discover the different percentage of deaths to births in different countries, we ought to feel no surprise at our being unable to discover where the check falls in any animal...
Стр. xxx - But I am strongly inclined to suspect that the most frequent cause of variability may be attributed to the male and female reproductive elements having been affected prior to the act of conception.