 | Charles Dickens - 1860 - 638 pàgines
...various birds which have been known occasionally to lay their eggs in other birds' nests. Lot us suppose that the ancient progenitor of our European cuckoo had the habits of the American cuckoo, but tliat she occasionally laid an egg in another bird's nest by way of experiment. If the old bird profited... | |
 | Paul Janet - 1866 - 216 pàgines
...automatically modified, as soon as any external circumstances disturbs them, it might be exactly the same case for natural instincts or habits originally stamped...the American cuckoo, but that occasionally she laid ah egg in another bird's - nest. If the old bird profited by this occasional habit, or if the young... | |
 | Charles Darwin - 1866 - 668 pàgines
...birds which have been known occasionally to lay their eggs in other birds' nests. Now let us suppose that the ancient progenitor of our European cuckoo...If the old bird profited by this occasional habit through being enabled to migrate earlier or through any other cause; or if the young were made more... | |
 | Charles Darwin - 1875 - 504 pàgines
...birds which have been known occasionally to lay their eggs in other birds' nests. Now let us suppose that the ancient progenitor of our European cuckoo had the habits of the American cuckoo, aud that »he occasionally laid an egg in another bird's nest. If the old bird profited by this occasional... | |
 | Charles Elam - 1876 - 184 pàgines
...builds its own nest ; probably the English cuckoo did so once, but perhaps accidentally and occasionally laid an egg in another bird's nest. If the old bird...occasional habit, or if the young were made more vigorous . . . then the old bird or the fostered young would gain an advantage. And analogy would lead me to... | |
 | John Holmes Agnew, Walter Hilliard Bidwell, Henry T. Steele - 1877 - 812 pàgines
...builds its own nest ; probably the English cuckoo did so once, but perhaps accidentally and occasionally laid an egg in another bird's nest. " If the old bird...occasional habit, or if the young were made more vigorous, . . . then the old bird, or the fostered young would gain an advantage. And analogy would lead me to... | |
 | 1877 - 1212 pàgines
...builds its own nest ; probably the English cuckoo did so once, but perhaps accidentally and occasionally laid an egg in another bird's nest. " If the old bird...occasional habit, or if the young were made more vigorous, . . . then the old bird, or the fostered young would gain an advantage. And analogy would lead me to... | |
 | 1881 - 1090 pàgines
...progenitor of the European cuckoo, had the habits of the American cuckoo, and that she occasionally laid an egg in another bird's nest. If the old bird profited by this occasional habit through being able to migrate earlier, or through any other cause; or if the young were made more vigorous... | |
 | George John Romanes - 1882 - 550 pàgines
...her own eggs, nevertheless occasionally deposits them in the nests of other birds. Now let us suppose that the ancient progenitor of our European cuckoo had the habits of the American cuckoo, and that x she occasionally laid her egg in another bird's nest. If the old bird profited by this occasional... | |
 | Franz Heinrich Reusch - 1886 - 396 pàgines
...that the ancestor of our European cuckoo had the same habits as the American, but yet occasionally laid an egg in another bird's nest. If the old bird profited by this occasional habit, or if the mistaken instinct of the strange mother caused the young bird to become stronger than he would have... | |
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Now let us suppose that the ancient progenitor of our European cuckoo had the habits of the American cuckoo, and that she occasionally laid an egg in another bird's nest. If the old bird profited by this occasional habit through being enabled to... 
