in THE SENSE OF TASTE 135 



To obviate this, Kit-sow and Halm employed a special s] 11 filled 



with a test solution which they introduced into the mouth after 

 depressing the tongue with a spatula, and bathed the uvula in it. 

 This experiment performed mi sixty individuals showed the uvula 

 to be insensitive to taste. Kiesow came to the same conclusion 

 from his histological researches. The soft palate and posterior 

 part of the fauces, on the contrary, possess a certain degree of 

 gustatory sensibility (Kiesow and Petersen). 



The discovery (referred to above) of taste-buds on the lower 

 surface of the human epiglottis (Verson) and on the lingual 

 surface of this organ in the foetus, and in one case in a subject 

 nineteen years old (Kiesow), and in the mucous membrane of 

 the arytenoid cartilage of the larynx (Davis) is surprising, and 

 these regions were also found to be sensitive to different sapid 

 substances (Gottchau, Langendorff and Michelson ; Kiesow). The 

 significance of this fact is not yet known. According to Kiesow 

 these must be phylogenetic vestiges, possibly still capable of 

 function, and concerned in the reflex coughing when sapid sub- 

 stances enter the larynx ; according to Zwaardemaker these 

 regions may possess gustatory sensations to gases, the so-called 

 nasal taste but on this point Kiesow expresses himself with 

 reserve. That this effect, perceived on inhaling gases, cannot be 

 referred to the mucous membrane of the nose seems positively 

 proved by the careful investigations of Eollett. 



Although it is the principal seat of taste the tongue is incapable 

 of perceiving flavours at all points of its surface. The region of 

 the circumvallate papillae is very sensitive, and from this region 

 the gustatory area extends along the margins of the organ to the tip. 

 Beyond the lingual V the individual variations in the distribu- 

 tion of the end-organs of taste are remarkable, not only as regards 

 their anatomical localisation, but also in the quality of the tastes 

 perceived. 



In adults a large oval area in the most central part of the 

 dorsum of the tongue, some 3 cm. wide and of variable length, is 

 insensitive to taste. 



The statements refer to taste sensibility in general ; but the 

 capacity of perceiving the quality of tastes does not seem to be 

 distributed equally over the surface of the tongue. This fact, 

 already known to the earlier observers (Horn 1825, Guyot and 

 Admirauld 1830), was sul tsequently confirmed and better defined 

 by other workers. The differences are particularly conspicuous 

 when the base and the tip of the tongue are examined separately. 

 Thus, according to Rouget, sodium chloride, which has a purely 

 saline taste on the front of the tongue, is slightly bitter if applied 

 to the V , and the same is true of nitrate and acetate of potassium. 

 According to Lussana, potassium chloride and sodium sulphate 

 have a saltish taste on the tip of the tongue : while the former is 



K I 



