SPLANCHNOLOGY 139 



The Hard Palate. — The hard palate, palatum durum, forming the 

 roof of the mouth has for its boundaries the beak anteriorly, the 

 mandibular arches laterally, and the pharynx posteriorly. It has 

 four or five transverse bars, projecting posteriorly from each of 

 which is a row of filiform papillae (Figs. 27 and 29). 



Fig. 30. — A section through the wall of the crop of a hen. i. The outer 

 muscidar layer showing longitudinal fibers. 2. The inner muscular layer showing 

 the sectioned ends of the bundles of muscle fibers. 3, Stratified 'squamous epi- 

 thelium. 4, The outer, surface or lumen of a fold. 5, The stroma, muscularis 

 mucosa, and submuoosa. 



The beak (Fig. 4, No. i) with little if any aid from the tongue, 

 is the prehensile organ. 



The Tongue (Fig. 27, No. 3). Location. — The tongue (lingua) of 

 the fowl is situated in the floor of the mouth between the rami of the 



H. From the cristas acoustica of the ampulla of the dove. A, A vertical section 

 with isolated fiber cells, i and 2, The nerve fibers. 3, The hair cells. 



I. A longitudinal section through a feather papilla showing a young feather. 

 I, The developing feather. 2, The horny sheath. 3, The epithelium. 4, 

 Stratum corneum. 5, Stratum malpighi. 6, Corium. 7, Malpighian cell 

 group of the follicle. 



