 | Richard Holt Hutton, Walter Bagehot - 1860 - 556 Seiten
...this limitation is due to the greater abundance in that area of a certain fly, which lays its eggs in the navels of these animals when first born. The...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... | |
 | 1860 - 564 Seiten
...this limitation is due to the greater abundance in that area of a certain fly, which lays its eggs in the navels of these animals when first born. The...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 - 1866 - 668 Seiten
...have shown that this is caused by the greater number in Paraguay of a certain fly, which lays its eggs in the navels of these animals when first born. The...must be 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 - 820 Seiten
...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 by other parasitic insects, llence, if certain insectivorous birds were to decrease in Paraguay, the parasitic... | |
 | Dr. Schmidt (Eduard Oskar), Oscar Schmidt - 1875 - 372 Seiten
...have shown that this is caused by the greater number in Paraguay of a certain fly, which lays its eggs in the navels of these animals when first born. The...must be habitually checked by some means, probably by other parasitic insects. Hence if certain insectivorous birds were to decrease in Paraguay, the parasitic... | |
 | Dr. Schmidt (Eduard Oskar), Oscar Schmidt - 1875 - 362 Seiten
...have shown that this is caused by the greater number in Paraguay of a certain fly, which lays its eggs in the navels of these animals when first born. The...must be habitually checked by some means, probably by other parasitic insects. Hence if certain insectivorous birds were to decrease in Paraguay, the parasitic... | |
 | Asa Gray - 1877 - 418 Seiten
...have shown that this is caused by the greater number in Paraguay of a certain fly, which lays its eggs in the navels of these animals when first born. The...probably by birds. Hence, if certain insectivorous birds (whoso numbers are probably regulated by hawks or beasts of prey) were to increase in Paraguay, the... | |
 | Alfred Russel Wallace - 1880 - 568 Seiten
...have shown that this is caused by the greater number in Paraguay of a certain fiy, which lays its eggs in the navels of these animals when first born. The...must be habitually checked by some means, probably by other parasitic insects. Hence, if certain insectivorous birds were to decrease in Paraguay, the parasitic... | |
 | Richard Anthony Proctor - 1883 - 438 Seiten
...have shown that this is caused by the greater number in Paraguay of a certain fly, which lays its eggs in the navels of these animals when first born. The...must be habitually checked by some means, probably by other parasite insects. Hence, if certain insectivorous birds do decrease in Paraguay, the parasite... | |
 | Charles Darwin - 1883 - 494 Seiten
...have shown that this is caused by the greater number in Paraguay of a certain fly, which lays its eegs in the navels of these animals when first born. The...numerous as they are, must be habitually checked by means, probably by other parasitic insects. Hence, if ccriain insectivorous birds were to decrease... | |
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Rengger have shown that this is caused by the greater number in Paraguay of a certain fly, which lays its eggs in the navels of these animals when first born. The increase of these flies, numerous as they are, must be habitually checked by some means,... 
