276 ORNITHOLOGY. 



crackers for extricating the kernel from the husk which cov- 

 ers it.* 



Varying as the beak does in different kinds of birds, it in no 

 instance performs a proper masticating function ; though it may 

 divide flesh, crack a nut, and with the assistance of the tongue, 

 shell it ; and though it may separate the grain from the husk, as 

 is constantly seen in the Goldfinch and Canary. A nearer ap- 

 proach to mastication, is the bruising down of hard seeds by 

 means of a knob in the middle of the palate, as is seen in the 

 Buntings. 



The stomach in Birds, consists of three parts, (not always, 

 however, distinctly developed,) viz., the crop or craw, the mem- 

 branous stomach, and the gizzard. From the want of masti- 

 cating power in the bird, it, of course, swallows its food entire. 

 When the food is flesh, the process of digestion is sufficiently 

 simple, and so rapid as to need no preparation. To prepare for 

 the digestion of hard grains and seeds, which are the food of so 

 large a number of species, a sort of internal grinding mill is fur- 

 nished by the gizzard. 



This organ, which is seen to most advantage in grain-eating 

 birds, is made up almost entirely of two semi-globular masses 

 of dense muscle, whose flat faces, covered with a thick leathery 

 skin, work over each other like a pair of millstones, and by the 

 aid of small angular stones, sand, etc., swallowed for the pur- 

 pose, very quickly grind down the hardest substances. In the 

 Museum of the College of Surgeons, (London,) is a large glass 

 bottle entirely filled with pebbles, &c., taken from the stomach 

 of an ostrich. The experiment has been made, without injury, 

 of conveying bullets beset with needles, and even lancets into 

 the stomachs of granivorous birds, with the effect of the total 

 destruction of those sharp instruments in a short period. 



The organs of the voice in birds bear a striking resem- 

 blance to certain musical wind instruments. The larynx is 

 made up of two parts ; the second part, or lower larynx, contains 

 a second rima glottidis, (cleft or opening of the throat,) furnished 

 with tense membranes which perform, in many birds, the same 

 office that a reed does in a clarionet, or hautboy, while the first 

 tor upper rima, (cleft or opening,) of the throat, like the ventage 

 or hole of the instrument, gives utterance to the note. None of 

 the endowments of this interesting class more minister to the 

 pleasure and delight of man than their powers of song. 



The development of the senses of birds varies in the different 



* See Penny Cyclopedia ; Art. Birds. 



