THE TONGUE. 21 



and in living persons, they may be procured in any quantity 

 by scraping the tongue. In twenty or thirty healthy young 

 people, I have hardly once failed to find the granular cover- 

 ing upon the epithelial processes, even in a perfectly clean, 

 red tongue. 



The more fur there is, the more abundant is the matrix, 

 and the mucedinous filaments are also apparent, though they 

 are rarely (three or four times in thirty cases) found so clear 

 and distinct as in fig. 176, and in general are not met with in 

 more than a third of those persons whose papilla filiformes are 

 not altogether in a normal condition. 



The physiological results of the anatomical data which have 

 been communicated, may be thus summed up : the papilla 

 filiformes are neither gustatory nor delicate tactile organs, since 

 their thick, and what is more to the point, greatly cornified 

 epithelium, is very little fitted to allow of the passage of fluids 

 capable of being tasted, or of other influences, to the scattered 

 nerves, which only attain to the base of the simple papillae. 

 With Todd and Bowman, I consider that the p. filiformes have a 

 similar office to the lingual spines of animals, which are nothing 

 but modified filiform papillae, and I therefore ascribe to them 

 a certain importance for the conveyance and retention of the 

 morsels of food, and I consider that their epithelium serves, at 

 the same time, as a protecting investment for the tongue. The 

 two other kinds of papillae subserve the sense of taste and are, 

 besides, the seat of ordinary sensation (for mechanical irritation, 

 temperatures, &c), for which functions they are excellently 

 fitted by their thin, soft epithelium, the softness of the tissue 

 of their papillae and by the superficial position (in the secondary 

 papillae), and the great number of their nerves. The sensibility 

 of the tongue is most delicate where the papilla fungiformes 

 are most closely set, i. e., at the apex, which, on that account, and 

 also perhaps by reason of the solid axile corpuscles in many of the 

 papillae, is especially fitted for a tactile organ ; at the root of the 

 tongue it is more obtuse, and is accompanied by peculiar sen- 

 sations ; the sense of taste is much more acute at the root of 

 the tongue than in the other regions, the point not excepted. 

 The reason of this lies neither in the epithelium, nor in the fun- 

 damental structure of the papillae, which are essentially similar 

 in both the papilla circumvallata and fungiformes, but is, very 



