SENSATIONS OF TASTE AND SMELL. 297 



and bitter tastes, etc., form a part of our daily experience, and 

 in the fused or compound sensation that results from such com- 

 binations one may usually recognize without difficulty the con- 

 stituent parts. The seemingly great variety of our taste sensations 

 is largely due to the fact that we confuse them or combine them 

 with simultaneous odor sensations. Thus, the flavors in fruits and 

 the bouquet of wines are due to odor sensations which we designate 

 ordinarily as tastes, since they are experienced at the time these 

 objects are ingested. If care is taken to shut off the nasal cavities 

 during the act of ingestion even imperfectly, as by holding the 

 nose, the so-called taste disappears in large measure. Very dis- 

 agreeable tastes are usually, as a matter of fact, due to unpleasant 

 odor sensations. On the other hand, some volatile substances 

 which enter the mouth through the nostrils and stimulate the 

 taste organs are interpreted by us as odors. The odor of chloro- 

 form, for instance, is largely due to stimulation of the sweet taste 

 in the tongue. 



Distribution and Specific Energy of the Fundamental 

 Taste Sensations. Regarding the distribution of the funda- 

 mental taste sensations over the tongue and palate there seem 

 to be many individual differences. In general, however, it may 

 be said that the bitter taste is more developed at the back of 

 the tongue and the adjacent or posterior regions; at the tip of 

 the tongue the bitter sense is less marked or in cases may be absent 

 altogether. On the contrary, in this latter region the sweet taste 

 is well developed. On this account it may happen that substances 

 which when first taken into the mouth give a not unpleasant sweet 

 taste subsequently when swallowed cause disagreeably bitter sen- 

 sations, like the little book of the evangelist, which in the mouth 

 was "sweet as honey, and as soon as I had eaten it, my belly was 

 bitter." Oehrwall * has made an interesting series of experiments 

 in which he stimulated separately a number of fungiform papillae 

 on the surface of the tongue. Each papilla was stimulated sepa- 

 rately for its fundamental taste senses of sweet, bitter, and acid, 

 by using drops of solutions of sugar, quinin, and tartaric acid. Of 

 the 125 papillae thus examined, 27 gave no reaction at all, although 

 sensitive to pressure and temperature. In the 98 papillae that 

 reacted to the sapid stimulation it was found that 60 gave taste 

 sensations of all three qualities, 4 gave only sweet and bitter, 7 only 

 bitter and acid, 12 only sweet and acid, 12 only acid, and 3 only 

 sweet. None was found to give only a bitter sensation. These 

 facts bear directly upon the question of the specific energy of the 

 taste fibers. It is possible that the four fundamental taste qualities 

 may be mediated by four different end-organs and four separate 

 * Oehrwall, "Skandinavisches Archiv f. Physiologie," 2, 1, 1890. 



