 | Charles Darwin - 1887 - 586 pàgines
...plants, it at once struck me that under these circumstances favourable variations would tend to be preserved, and unfavourable ones to be destroyed....this would be the formation of new species. Here then I had at last got a theory by which to work ; but I was so anxious to avoid prejudice, that I determined... | |
 | Charles Darwin - 1887 - 588 pàgines
...plants, it at once struck me that under these circumstances favourable variations would tend to be preserved, and unfavourable ones to be destroyed....this would be the formation of new species. Here then I had at last got a theory by which to work ; but I was so anxious to avoid prejudice, that I determined... | |
 | Charles Darwin - 1887 - 570 pàgines
...plants, it at once struck me that under these circumstances favourable variations would tend to be preserved, and unfavourable ones to be destroyed....this would be the formation of new species. Here then I had at last got a theory by which to work ; but I was so anxious to avoid prejudice, that I determined... | |
 | 1888 - 386 pàgines
...plants, it at once struck me that under these circumstances favourable variations would tend to be preserved and unfavourable ones to be destroyed. The...would be the formation of new species. Here, then, I had at last got a theory by which to work ; but I was so anxious to avoid * LETTERS OF DAVID RICARDO... | |
 | William Parker Cutler - 1888 - 1034 pàgines
...plants, it at once struck me that under these circumstances favourable variations would tend to be preserved, and unfavourable ones to be destroyed....this would be the formation of new species. Here then I had at last got a theory by which to work ; . but I was so anxious to avoid prejudice, that I determined... | |
 | Thomas Robert Malthus, George Thomas Bettany - 1890 - 714 pàgines
...plants, it at once struck me that under these circumstances favourable variations would tend to be preserved, and unfavourable ones to be destroyed....would be the formation of new species. Here, then, I had at last got a theory by which to work." (Now that it is very generally recognised that this struggle... | |
 | Charles Frederick Holder - 1891 - 374 pàgines
...the idea that in the struggle for existence between various forms, " favourable variations tend to be preserved, and unfavourable ones to be destroyed. The result of this would be the formation of a new species." The idea must have come to him like a sudden flash of light that was, indeed, to illumine... | |
 | Charles Darwin - 1892 - 372 pàgines
...plants, it at once struck me that under these circumstances favourable variations would tend to be preserved, and unfavourable ones to be destroyed....would be the formation of new species. Here, then, I had at last got a theory by which to work ; but I was so anxious to avoid prejudice, that I determined... | |
 | W. T. B. Martin, T. E. S. T. - 1894 - 536 pàgines
...plants, it at once struck me that under . . . circumstances favourable variations would tend to be preserved, and unfavourable ones to be destroyed....result of this would be the formation of new Species. But at that time I overlooked one problem of great importance. . . . This is the tendency in organic... | |
 | Benjamin Kidd - 1894 - 372 pàgines
...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 foundation of a new species. Here, then, I had at last got a theory by which to work." — The Life... | |
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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... 
