TASTE OP GRANIVOROUS BIRDS. 113 



the termination of the gullet, and running along the 

 front towards the gizzard. This band measures about 

 twelve inches in length, and is about three inches at 

 its greatest breadth. It is remarkable that this organ 

 with its glands is largest in such birds as feed upon 

 substances hardest of digestion. In some other birds 

 it is, as we shall afterwards see, very small, and in 

 others (Alcedo) wanting altogether*. 



The gizzard (ventriculus callosus) is a cavity of 

 moderate size and of a flat spherical form, composed, 

 according to Grewf, of six, and according to others 

 of four, distinct muscles ; but the discrepancy is ex- 

 plained by considering two of the six as conductors of 

 the food, rather than as forming a portion of the organ, 

 the greater part of which is composed of only two 

 muscles, of a peculiarly dense and firm texture, hemi- 

 spherical in shape, and lined with a thick membrane of 



Cardiac cavity and g'i2zard of the Ostrich, opened to show its 

 internal structure. 



* Blumenbach, Comp. Anat. 97. 

 t Comp. Anat. of the Stomach, p, 34. 



