312 



INTRODUCTION TO ZOOLOGY. 



which, thickened in its coats, performs the same office as the 

 teeth of the graminivorous quadrupeds. 



Fig. 248. DIGESTIVE APPARATUS OF A FOWL.* 



The action of the gizzard is expedited by small pehhles 

 and other hard substances swallowed hy the fowl. In the 

 Ostrich (Fig. 249), this instinctive action prevails to such an 

 extent, that in the stomach of one were found pebbles suffi- 

 cient to fill a large glass bottle; and as the Ostrich will 



* e, oesophagus; C, crop; v, ventriculus succenturiatus; g 1 , gizzard; /, liver; 

 gb, gall-bladder ; 6, bile-ducts ; p, pancreas ; d, duodenum ; c, coeca ; s, small in- 

 testine ; L, large intestine ; 0, oviduct. 



