136 ANATOMY OF THE DOMESTIC FOWL 



an inner soft part. .The outer part is covered by epithelium which 

 may be considered as a continuation from the upper outer portion 

 of the beak. A portion of this is cornified. The inner part is cov- 

 ered by a mucous membrane containing mucous glands, nerves, and 

 blood-vessels. 



In the posterior part of the upper half of the mouth, are situated 

 the posterior nares (Fig. 27, No. 10) which appear as a longitudinal 



FIG. 27. Mouth and pharynx of a cock laid open, i, Eye. 2, Edge of beak 

 covered with a horn-like gum. 3, Tongue. 4, Pharynx. 5, Posterior cross bar 

 of hard palate. 6, Posterior end of tongue. 7, Anterior end of esophagus. 

 8, Phrenum. 9, Palatal papillaries. 10, Posterior nares. 



slit in the center of the hard palate. There is also found in this 

 part a furrow which contains the opening of the Eustachian tubes, 

 or tubae auditivae. There are also two ridges near the same pos- 

 terior part in which are red and white papillae, which may appear 

 in rows, and which contain mucous glands. 



The lower half of the mouth lies between the lower jaw bones and 

 the walls of the mouth cavity. The tongue is attached here by 



