224 FACULTIES OF BIRDS. 



both this and the instance given by M. Adanson 

 show the circumstance to be of unusual occur- 

 rence. 



A British bird, the bustard (Otis tarda, RAY), 

 now rarely seen, if not extinct, is very similar to the 

 ostrich in its faculty of running', being so fleet as to 

 be hunted with greyhounds, a sport followed even 

 by the ancient Greeks, as we learn from Xenophon 

 and jElian. The male of this species is furnished 

 with a singular bag or pouch, opening under the 

 tongue, and hanging down on the fore part of the 

 gullet, as low as the middle of the neck. This seems 

 to have been first observed by Aristotle *, but was 

 particularly described by Dr. Douglas, who imagined 

 it was intended as a reservoir for water, indispensable 

 in the extensive arid plains which it inhabits. He 

 found it capacious enough to hold several quarts 

 of water. Colonel Montagu, however, seems to be 

 somewhat sceptical upon this point. " We think 

 it impossible," he says, "that the bird could fly 

 with such an addition of weight before its wings, 

 which would throw it out of the centre of gravity. 

 We see the heron, and many other birds, obliged 

 to extend their legs behind, and contract their necks 

 when flying, in order to balance themselves on the 

 wing. Seven quarts of water (the quantity mentioned 

 by Dr. Douglas) are nearly equal to fourteen pounds 

 weight, and certainly more than the bird could carry 

 in that situation^." It would appear indeed from 

 the observations of Sir Everard Home that Montagu's 

 objections are valid ; for in the adjutant (Ciconia 

 argala, TEMMINCK), which has a bag precisely 

 similar, he found that it contained " nothing but 

 air, which the bird has a power of expelling and 

 filling the bag again at pleasure." In the adjutant 



* Hist. Anim. lib. ii. sub. fin. 

 t Ornith. Diet. p. 63. 



