THE SENSE OF TASTE. 623 
dog and kindred animals probably have a world of their own 
to no small extent. Their memory of smells is also immeasur- 
ably better than our own. A dog has been known to detect an 
old hat, the property of his master, that had been given away 
two years before, as evidenced by his recovering it from a 
remote place. 
The importance of smell as a guide in the selection of food, 
in detecting the presence of prey or of enemies, etc., is very 
obvious. By culture some persons have learned to distinguish 
individuals by smell alone, like the dog, though to a less degree. 
THE SENSE OF TASTE. 
The tongue is provided with peculiar modifications of epi- 
thelial cells, etc., known as papille and taste-buds which may 
be regarded as the end-organs of the glosso-pharyngeal and 
lingual nerves; though that these all, especially the taste-buds, 
are concerned with taste alone, seems more than doubtful. In 
certain animals with rough tongues, the papille, certain of 
them at least, answer to the hairs of a brush for the cleansing 
and general preservation of the coat of the animal in good con- 
dition, We may, perhaps, speak of certain fundamental taste- 
perceptions, such as sweet, bitter, acid, and saline. Certainly 
the natural power of gustatory discrimination is considerable; 
and, as in the case of tea-tasters, capable of extraordinary culti- 
vation. All parts of the tongue are not equally sensitive, nor 
is taste-sensation confined entirely to the tongue. It can be 
shown that the back edges and tip of the tongue, the soft palate, 
the anterior pillars of the fauces, and a limited portion of the 
back part of the hard palate, are concerned in tasting. Making 
allowances for individual differences, it may be said that the 
back of the tongue appreciates best bitter substances, the tip, 
sweet ones, and the edges acids. 
If any substance with a decided taste be placed upon the 
tongue when wiped quite dry, it can not be tasted at all, show- 
ing that solution is essential. 
If a piece of apple, another of potato, and a third of onion, 
be placed upon the tongue of a person blindfolded, and with 
the nostrils closed, he will not be able to distinguish them, 
showing that the senses of smell and of taste are related; or, 
perhaps, it may be said that much that we call tasting is in 
large part smelling. When the electrodes from a battery are 
