NATURE STUDY JN SCHOOLS. 



101 



has become greatly enlarged, while the grinding, or muscular, sometimes known 

 as the gizzard, is very small. This large first stomach serves two purposes, 

 first, in retaining the ants till they are thoroughly mixed with the digestive fluid 

 which exudes from glands with which the walis of this stomach are provided, 

 second, the digestive surface is increased. The glands themselves are not only 

 numerous, but each gland is furnished with small projections arranged around 



Fi<*. 54. 



A, bill of Yucatan ivory-billed woodpecker; B, tongue of downy woodpecker, enlarged ; C. bill of 

 tiicker ; D, tongue of same, 



a central gland. This may be understood by referring to fig. 53, A, where 

 is given an enlarged view of a single gland. The stomachs and other diges- 

 tive organs, figured with it, are life size and the parts are explained beneath 

 the cut. Stomach and tongue of other species of woodpecker will be figured 

 in a forthcoming number of Nature Study. 



