49 



CHAPTER III. 



INTERNAL STRUCTURE. DIGESTIVE ORGANS. GULLET, CROP, 



STOMACH ADAPTATION OF, TO DIFFERENT HABITS OF BIRDS. 



GASTRIC JUICE ITS USE AND PROPERTIES. GIZZARD, ITS 

 GRINDING POWERS. RESPIRATION OF BIRDS. 



HAVING briefly pointed out the most prominent 

 features of the skeleton, as influencing the general 

 form of birds, we shall now proceed to give a short 

 sketch of the structure and uses of some of the 

 internal parts, commencing with those for the sup- 

 ply and consumption of food. The following figure 

 may assist our explanation. 



VOL. I. 



