DIGESTION. 



165 



is discharged into the cavity of the stomach. The 

 gastric glands of birds are larger and more con- 

 spicuous than those of quadrupeds; but, indepen- 

 dently of those which are situated in the stomach, 

 there is likewise found, in almost all birds, at the 

 lower termination of the oesophagus, a large glan- 

 dular organ, which has been termed the hulbulus 

 glandulosus. In the Ostrich, this organ is of so 

 great a size as to give it the appearance of a sepa- 

 rate stomach. A view of the internal surface of 

 the stomach of the African ostrich is given in Fig. 

 302 ; where c is the cardiac cavity, the coats of 



303 



304 



which are studded with numerous glands ; g, g, 

 are the two sides of the gizzard. Fig. 303 shows 

 one of the gastric glands of the African ostrich ; 

 Fig. 304, a gland from the stomach of the American 

 ostrich ; and Fig. 305, a section of a gastric gland 

 in the beaver, showing the branching of the ducts, 

 which form three internal openings. In birds that 

 live on vegetable food, the structure of the gastric 

 glands is evidently different from that of the corres- 

 ponding glands in predaceous birds ; but as these 



