| 1860 - 966 páginas
...never flying."* Then in tLe s;une page the author adds that certain considerations have mude him " believe that the wingless condition of so many Madeira...is mainly due to the action of natural selection, but combined probably with disuse. For during thousands of 4ii-Cf4<ive generations each individual... | |
| Charles Darwin - 1861 - 470 páginas
...have habits of life almost necessitating frequent flight ; — these several considerations have made me believe that the wingless condition of so many...is mainly due to the action of natural selection, but combined probably with disuse. For during thousands of successive generations each individual beetle... | |
| Charles Darwin - 1864 - 472 páginas
...have habits of life almost necessitating frequent flight ; — these several considerations have made me believe that the wingless condition of so many...is mainly due to the action of natural selection, but combined probably with disuse. For during thousands of successive generations each individual beetle... | |
| 1879 - 978 páginas
...Madeira. How may the absence of wings in the Madeiran beetles be accounted fo^- ? Let Mr. Darwin reply : " Several considerations make me believe that the wingless...is mainly due to the action of natural selection, combined probably with disuse. For during many successive generations each individual beetle •which... | |
| Charles Darwin - 1873 - 492 páginas
...numerous, which absolutely require the use of their wings, are here almost entirely absent;—these several considerations make me believe that the wingless...is mainly due to the action of natural selection, combined probably with disuse. For • during many successive generations each individual beetle which... | |
| Charles Elam - 1876 - 186 páginas
...Mivart, in his Lessons from Nature, p. 300. 2 Origin of Species, p. 136. NATURAL SELECTION. 127 less condition of so many Madeira beetles is mainly due to the action of natural selection, but combined probably with disuse. For during thousands of successive generations each individual beetle... | |
| John Holmes Agnew, Walter Hilliard Bidwell, Henry T. Steele - 1877 - 812 páginas
...never flying." * Then in the same page the author adds that certain considerations have made him " believe that the wingless condition of so many Madeira...is mainly due to the action of natural selection, but combined probably with disuse. For during thousands of successive generations each individual beetle... | |
| 1877 - 1212 páginas
...the same page the author adds that certain considerations have made him " believe that the wiiigless condition of so many Madeira beetles is mainly due to the action of natural selection, but combined probably with disuse. For during thousands of successive generations each individual beetle... | |
| Samuel Butler - 1879 - 436 páginas
...and that though it would be easy to set it down to disuse, yet we must on no account do so. The facts having been stated, Mr. Darwin continues:— " These...do with the matter. We feel a languid wish to know exactly how much and in what way it has entered into the combination ; but we find it difficult to... | |
| 1879 - 794 páginas
...Madeira. How may the absence of wings in the Madeiran beetles be accounted for ? Let Mr. Darwin reply : " Several considerations make me believe that the wingless...is mainly due to the action of natural selection, combined probably with disuse. For during many successive generations each individual beetle which... | |
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