 Paraguay offers the most curious instance of this; for here neither cattle nor horses nor dogs have ever run wild, though they swarm southward and northward in a feral state; and Azara and Rengger have shown that this is caused by the greater number in...  Mysteries of Time and Space - Стр. 373авторы: Richard Anthony Proctor - 1883 - Страниц: 418Полный просмотр - Подробнее о книге
 | 1909 - Страниц: 844
...abounded in profusion, but in Paraguay itself they had become extinct. This was caused by the existence in Paraguay of a certain fly, which lays its eggs in the navels of these animals and so produces disease and death. There do not appear to be enough parasitic insects to keep down... | |
 | 1866 - Страниц: 808
...have ever run wild, though they swarm southward and northward in a feral state ; and Azara and Rengger have shown that this is caused by the greater number...must be habitually checked by some means, probably by birds. Hence if certain insectivorous birds (whose numbers are probably regulated by hawks or beasts... | |
 | 1860 - Страниц: 982
...have ever run wild, though they swarm southward and northward in a feral state ; and Azara and Rengger have shown that this is caused by the greater number...must be habitually checked by some means, probably by birds. Hence, if certain insectivorous birds (whose numbers are probably regulated by hawks or beasts... | |
 | 1860 - Страниц: 564
...and northward, in a feral state ; and this limitation is due to the greater abundance in that area of a certain fly, which lays its eggs in the navels...these flies, numerous as they are, must be habitually kept in check by some means, probably by birds. Hence, if certain insectivorous birds (whose numbers... | |
 | Richard Holt Hutton, Walter Bagehot - 1860 - Страниц: 556
...and northward, in a feral state ; and this limitation is due to the greater abundance in that area of a certain fly, which lays its eggs in the navels...these flies, numerous as they are, must be habitually kept in check by some means, probably by birds. Hence, if certain insectivorous birds (whose numbers... | |
 | Charles Darwin - 1861 - Страниц: 470
...ever run wild, though they swarm, southward and northward in a feral state ; and Azara and Rengger have shown that this is caused by the greater number...must be habitually checked by some means, probably by birds. Hence, if certain insectivorous birds (whose numbers are probably regulated by hawks or beasts... | |
 | Charles Darwin - 1864 - Страниц: 472
...have ever run wild, though they swarm southward and northward in a feral state ; and Azara and Eengger have shown that this is caused by the greater number...must be habitually checked by some means, probably by birds. Hence, if certain insectivorous birds (whose numbers are probably regulated by hawks or beasts... | |
 | Charles Darwin - 1866 - Страниц: 668
...have ever run wild, though they swarm southward and northward in a feral state ; and Azara and Rengger have shown that this is caused by the greater number...habitually checked by some means, probably by other parasitic insects. Hence, if certain insectivorous birds were to decrease in Paraguay, the parasitic... | |
 | 1906 - Страниц: 960
...northward in a feral state; and Azara and Rengger have shown that this is caused by the greater numbers, in Paraguay, of a certain fly which lays its eggs...habitually checked by some means, probably by other parasitic insects. Hence, if certain insectivorous birds were to decrease in Paraguay, the parasitic... | |
 | Norfolk and Norwich Naturalists' Society - 1884 - Страниц: 820
...Azara and Kengger have shown that tin's is caused by the greater number in Paraguay of a certain By which lays its eggs in the navels of these animals when first bom. The increase of these Hies, numerous as they are, must be habitually checked by some means, probably... | |
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