PHYSIOLOGY OF GUSTATION 



149 



of importance to ascertain in what other respects they 

 are independent. This question can be well approached 

 from the standpoint of their distribution on the tongue. 

 As already mentioned, the tongue of the normal adult 

 human being is only in part gustatory, its lower surface 

 and the central portion of its upper surface being 



m 



U?..?j 



A B C D 



FIG. 36. Diagrams of the right half of the human tongue illustrating the distribution of 

 the four tastes; the dots represent the area and concentration of a given taste: A, the sour 

 taste, concentrated on the edge; B, the saline taste, concentrated at the tip and on the edge; 

 C, the bitter taste, concentrated at the base; D, the sweet taste, concentrated at the tip. 

 Modified from Hanig, 1901. 



devoid of taste. This sense is resident only on the 

 tip, the edges and the dorsal part of the root of the 

 tongue. The distribution of the several tastes over the 

 gustatory portion of the tongue has been a matter of 

 investigation for physiologists during more than a cen- 

 tury, and the results, particularly among the recent 

 workers, have been remarkably consistent and harmoni- 

 ous. Shore (1892), Kiesow (1894-1896), and Hanig 

 (1901) have been the most important recent contributors 



