304 



COMPARATIVE ANATOMY 



their sides they bear numerous taste-buds. Their number varies from six 

 to twelve, and they occur in a V-shaped row just in front of the sulcus 

 terminalis. Of the various forms of papillae on the tongue the filiform 

 papillae are the most numerous. Each filiform papilla is covered with 

 filamentous processes. Foliate papillae are three to eight parallel folds 

 on each side of the tongue. Like the vallate papillae, the foliate papillae 

 have taste-buds. The fungiform papillae are scattered over the entire 

 dorsum of the tongue, and are distinguished by their reddish color and 



EPIGLOTTIS. 



FOLIATE 

 PAPILLAE 



Fig. 255. — The dorsal surface of the tongue. The sulcus terminalis divides the 

 body or apex of the tongue from the root. The two regions have a different embryonic 

 origin. (Redrawn after Sobotta.) 



their globular mushroom shape. They also bear taste-buds. No papillae 

 occur on the posterior and inferior surfaces of the tongue. (Fig. 255) 



Most of the mass of the tongue consists of striated muscle. In the 

 connective tissue corium of the tongue, both mucus and serous glands are 

 abundant. The lingual tonsils lie on the posterior dorsum. 



Development of the Tongue. The apex and root of the tongue, which 

 develop from separate anlagen, remain throughout life divided by the 

 sulcus terminahs. The apex of the tongue is formed by the union of a 

 median tuberculum impar with the basal portions of the two halves of the 



