PHYSIOLOGY OF GUSTATION 151 



tested. All of these were found to be sensitive to touch, 

 warmth, and cold, but only 98 were stimulated by the 

 solutions used. The results of these tests so far as they 

 relate to taste are given in the following tabulation. 



Test Substances Acid Quinine Sugar 



Number of papillae sensitive 91 71 79 



Number exclusively sensitive) 12 3 



The fact that 12 papillae were stimulated by tartaric 

 acid but not by quinine or sugar and that 3 were stimu- 

 lated by sugar but not by tartaric acid or quinine is strong 

 evidence in favor of the independence of at least the sour 

 and sweet tastes. Oehrwall also discovered by his 

 method of local stimulation that the surface of the tongue 

 between the papillas was insensitive to taste. 



This result confirmed the earlier work of Goldscheider 

 and Schmidt (1890) who had also shown that when pa- 

 pillas were tested with a mixed solution of sugar and 

 quinine sometimes a sweet taste was evoked and at other 

 times a bitter one. 



This whole subject was thoroughly re-investigated by 

 Kiesow (1898), who used as stimuli solutions of hydro- 

 chloric acid, of sodium chloride, of quinine sulphate and 

 of sugar. Of the 39 papillae tested 4 were found to be 

 insensitive. The conditions presented by the remaining 

 35 are summarized in the following tabulation. 



Test Substances Acid Salt Quinine Sugar 



Number of papillae sensitive 18 18 13 26 



Number exclusively sensitive 3307 



Failed of stimulation 17 17 22 9 



These results confirm and extend the original findings 

 of Oehrwall in that they show the independence of the 

 sour, saline, and sweet tastes. The fact that the region 



