86 TlIE FEATHERED TRIBES. 



boat, in wliicli position it remained during several days, displaying no disposition to mis- 

 chief, but constantly refusing all kinds of food. 



Our aciiuaintance with the Harpy eagle, in a state of nature, is unavoidably incom- 

 plete. In capti\'ity, there is little to distinguish it from other birds of the same tribe. 

 One individual, taken from the nest, became so tame as to suffer its head to be handled 

 and scratched ; but, unhappOy, it was found dead in its passage to Europe. It is sup- 

 posed to have fallen a victim to the vengeance of the sailors. Their monkeys, in their 

 gambols, unconsciously approached too near the cage of tliis powerful bird, which seized 

 them with its mighty talons, and having skinned them, devoured them with almost all 

 their bones. 



One of these birds hved long in the Menagerie of the Tower of London, and another 

 hi the Gardens of the Zoological Society. 



As we can give only some of the most remarkable specimens of the different families 

 of birds, it will be well, before we proceed, to glance at some striking facts in reference 

 to the eagles, on various examples of which we have now been dwelling. It may, how- 

 ever, be premised that, m common with other birds, they enjoy the advantage of a 

 remarkable defence from too strong sight, which consists of the membrana nictitans, the 

 nictitating membrane. In the human eye, there is a little red fleshy membrane, in the 

 form of a crescent, which may be observed in a looking-glass, by turning the eye away 

 as far as possible from the nose. The membrane, in such a position of the eye, is 

 spread over its mner angle, and when any dust has fallen on the. ball, it sticks to this, 

 and is carried mto the corner of the eye, by the membrane folding back. But in birds, 

 this membrane is much more extended, and is spread over the whole eye by means of 

 two muscles, one forming a tendonous cylindrical canal, the other passing through this, 

 and working like a cord in a pulley. The membrane being translucent when it is drawn 

 over the eye like a curtain, is well calculated to protect the organ from being dazzled by 

 an excess of light. 



The Abb6 Spallanzani made several experiments on the digestive powers of the eagle, 

 which, he says, was the common eagle of Buffon, and the black eagle of LimiiBus, both 

 synonymous with the golden eagle.* 



" The ordmary food of my eagle," says the Abb^, " consisted of live cats and dogs 

 when I covUd procure them. It easily kiDed dogs much larger than itself. When I 

 forced one of these animals into the apartment where I kept the eagle, it immediately 

 ruffled the feathers on the head and neck, cast a dreadful look at the dog, and taking a 

 short flight, immediately ahghted on his back. It held the neck firm with one foot, by 

 which the dog was prevented from turning his head to bite ; and with the other grasped 

 one of the flanks, at the same time driving the talons into the body ; and in this atti- 

 tude it continued till the dog expired, in the midst of fruitless cries and efforts. The 

 beak had been hitherto unemployed, but it was now used for making a small hole in 

 the skin, which Wixs gradually enlarged ; from this the bird began to tear away and 

 devour the flesh, and went on till it was satisfied. I must not omit observing that it 

 never eat any skin, nor intestine, nor bone, except very small ones, such as the ril)S 

 of cats and small dogs. Notwithstanding this ferocity, and violent impetuosity m attack- 

 ing animals, it never gave any molestation to man. I, who was tlie feeder, could safely 

 enter the apartment where the bii-d was kept, without any means of confining its move- 



<li iill||iiluu\ . Ii\ li,[\ , p. .'>H. 



