THE ALIMBJfTAET SYSTEM. 



207 



the tongue, supported by its " os hyoides " *, and behind the 

 tongue is an opening, called the glottis, which leads into the 

 windpipe and so iuto the lungs. 



Into the base and sides of the mouth open the spittle-glands 

 or salivary glands, which are usually small and simple, but may, 

 as in the Woodpecker, be considerably developed. 



Fig. 161. 



VlSCERA OF THE FoWL. 



ce, (Esophagus ; cp, crop ; po, proventrieulus ; ff, gizzard ; I, liver ; ffb, gall- 

 bladder ; p, pancreas ; d, loop of the duodenal part of the intestine 

 enclosing the pancreas ; si, small intestine ; li, large intestine ; c, caeca ; 

 0, oviduct ; u, ureter. — The cloaca is cut open, and some feathers are 

 represented as attached to its margin. 



The tongue may be of large size, and soft as in the Parrot ; it 

 may be a horny spine, as in the "Woodpecker. It may form 

 two delicate tubes, side by side, as in the Humming-bird ; it 



* See ante, ^.187. 



