OF THE GIZZARD. 291 



tion necessary to make the teeth last for the full 

 period of the life of a graminivorous quadruped, 

 we are prepared to understand the advantage of 

 this beautiful and simple substitute, which, to so 

 small a creature as a pigeon, gives an equal power 

 over the material of its food, as the horse has 

 with its powerful jaws, and strong grinding teeth. 



However, we are but describing a new instru- 

 ment for grinding, or comminuting the food : yet 

 this alone is not sufficient to supply what was 

 wanting in the mouth ; and in passing, we may 

 observe that the gizzard does not exclusively 

 belong to birds. The gillaroo trout and the mul- 

 let have gizzards. The toothless anteater has a 

 gizzard : it lives on scaly and hard insects, such as 

 beetles ; and to assist in bruising them in its 

 muscular stomach, it picks up pebbles like the 

 domestic fowl. 



Before the grain descends into this grinding 

 apparatus of the bird, it is deposited in the crop ; 

 from the crop it descends, by little and little, into 

 the cardiac cavity, as the first part of the stomach 

 is called. In this latter cavity there are glands 

 which secrete the gastric juice, and which fluid 

 is necessary to digestion. We should here also 

 note a particular provision in the upper orifice of 

 the gizzard, namely, the overlapping of a part 

 of the muscle, which produces an obliquity in the 

 passage, and holds the contents of the stomach 

 confined during the strong action of grinding. 

 It was indeed at one time supposed that such a 



