INSTINCTS OF BIRDS. 281 



taken into consideration. But even supposing 

 this notion to be correct, it does not in the least 

 affect the instinctiveness of the act; unless we 

 conclude with Darwin, that instinct has nothing 

 to do with any of those actions which result from 

 the repeated efforts of the muscles under the 

 conduct of the sensations or desires ; an opinion 

 so manifestly erroneous that it does not require 

 a formal refutation. 



The habits and manners of birds are sometimes 

 so greatly modified by the exercise of the intel- 

 lectual faculties, that, in many cases, it becomes 

 extremely difficult, if not impossible, to deter- 

 mine what is due to their influence ; but that no 

 small portion of intelligence is exhibited in the 

 following instances will scarcely be denied. 



The white-headed eagle and several of the 

 gulls, which prey upon the finny inhabitants of 

 the waters, frequently save themselves the trou- 

 ble of fishing, by robbing their more expert and 

 less powerful congeners of the fruits of their 

 industry, occasionally compelling the objects of 

 their violence, even to disgorge their undigested 

 food.* 



* John James Audubon, Esq., the celebrated author of the 

 splendid work on American Ornithology now publishing in 

 London, informs me that when the white-headed eagle pursues 



2 N 



