Dynamic Theory. 

 The filiform papillae subdivide into at least two varieties which grade 

 into each other, one sort are conical, as shown in fig. 224, and the other 

 is cylindrical and has a brush of filaments on top, each of which is cov- 

 ered with scales. These filaments appear to be something in the nature 



the 



FiG.223.Fungiform Papilla of the 



Tongue. 

 A. Body of one primary papilla cov- 



ered with secondary papillae s : and 



epithelium d. 



.5. Section of same a artery ; v vein. 

 ( Todd and Bowman. ) 



-c, 



Ton Se 224: -~ Conical 



a. Basal Membrane. 



p. Body of the Papilla or " Process" 



. on which rise the tactile papillae. 

 /.Superficial layer of epithelium. 

 e. Lower layer of epithelium. 

 IkThe points from which the filaments 

 project. (Hyde Salter.) 



of cilia, and are said to be "protective" and 

 1 1 portative. " The conical sort are mainly 

 organs of touch, while the mushroom or fun- 

 giform sort, and the large circumvallate ones 

 are the true organs of taste. The gustatory 

 branch of the 5th nerve supplies the fungi- 

 form, conical and filiform papillae, while the 



FIG. 225. Two Filiform Pavillse of the Tongue, one with 



epithelium, the ether without. 

 jo. Body of the papilla. 



s. Secondary papillae springing from the primary ones. 

 e. Epithelium laminated below. 

 d. Filaments springing from it covered with scales, the 



excess of which constitutes the "fur" of the tongue. 

 a. Artery. v. Vein. ( Todd & Bowman.) 



glosso-pharyngeal supplies the fossulate papil- 



lae, and the mucous tract behind. ( Owen. ) 



Experiments have shown that animals lose 



their discrimination of taste when the glosso- 



pharyngeal nerve is cut, for they will then eat 



disgusting food which, in their normal condi- 



dition, they would reject. Very minute investigations into the structure 



of the taste papillae by Loven and Schwalbe have shown that in the 



epithelium of these papillae there are many bud-like groups of cells with 



which the ultimate fibres of the glosso-pharyngeal nerve are connected. 



These cells have been termed " taste buds." In man they are shaped 



like a flask, in some other animals they are more slender. < ' In the 



225. 



