ORGANS OF DIGESTION. 113 
' There are seven openings into the pharynx: the two 
posterior nares (Fig. 18), opening anteriorly from the 
roof; a Eustachian tube on each side; the esophagus; and 
the Jarynv, leading into the trachea. The mucous mem- 
brane lining the pharynx contains many simple microscopic 
mucous glands. 
VISCERA. 
The body cavity known as the calom must be opened 
before the rest of the alimentary canal can be displayed. 
The entire ventral wall of the thoracic and abdominal cavi- 
Fic. 59. VIScERA OF THE HuMAN Bopy.—(Deaver.) 
co, Colon; li, liver; lu, lung; si, small intestine; st, stomach. 
II 
