TASTE. 



571 



tongue, and the lingual brandies of the inferior maxillary 

 division (p. 170) of the trigeminals on its anterior two 

 thirds. 



On the tongue the nerves run to papillae; the circumval- 

 late (p. 313) have the richest supply, and on these are cer- 

 tain peculiar end organs (Fig. 155) known as taste-buds, 

 which are oval and imbedded in the epidermis covering the 

 side of the papilla. Each consists, externally, of a number 

 of flat, fusiform, nucleated cells and, internally, of six or 

 eight so-called taste-cells. The latter are much like the 

 olfactory cells of the nose, and are probably connected with 

 nerve-fibres at their deeper ends. The capsule formed by 

 the enveloping cells has a small opening on the surface^ 



FIG. 155. Taste-buds. 



each taste-cell terminates in a very fine thread which pro- 

 trudes there. Taste-buds are also found on some of the 

 fungiform papillae, and it is possible that simpler struc- 

 tures, not yet recognized, consisting of single taste-cells 

 are widely spread on the tongue, since the sense of taste 

 exists where no taste-buds can be found. The filiform 

 papillae are probably tactile. 



In order that substances be tasted they must be in solu- 

 tion: wipe the tongue dry and put a crystal of sugar on it; 

 no taste will be felt until exuding moisture has dissolved 

 some of the crystal. Tastes proper may be divided into 

 sweet, bitter, acid, and saline. Intellectually they are, like 

 smells, of small value; the perceptions we attain through 

 them as to qualities of external objects being of little use, 



