SENSATION 



their action, a minimum below which they fail to 

 stimulate, and an optimum or stage in which their 

 influence is strongest. 



The important part played in human life by taste and 

 the pleasure associated with it is well known. The careful 

 choice and preparation of savory food — which has be- 

 come an art in gastronomy and a branch of practical phi- 

 losophy in gastrosophy — was just as important two thou- 

 sand years ago with the Greeks and Romans as it is to-day 

 in royal banquets or the Lucullic dinners of millionaires. 

 The excitement that we see associated with this refined 

 combination of rich foods and drinks, and that finds 

 expression in so many speeches and toasts, has its philo- 

 sophic root in the harmony of gustatory sensations and 

 the varying play of stimuli that the delicate dishes and 

 wines exercise on the organs of taste, the tongue and 

 palate. The microscopic organs of these parts of the 

 mouth are the gustatory papillae — cup-shaped structures, 

 covered with spindle-shaped "taste-cells," and having a 

 narrow opening into the cavity of the mouth. When sapid 

 matters, drinks and fluid or loose particles of food, touch 

 the taste-cells, they excite the fine terminal branchlets of 

 the gustatory nerve which enters the cells. As we find 

 that there are similar structures in most of the higher 

 animals, and that they also choose their food with some 

 care, we may confidently assume that they have sensa- 

 tions of taste like man. However, no trace of this is 

 found in many of the lower animals; in these cases it is 

 impossible to lay down a line of demarcation between 

 taste and smell. 



In man and the higher air-breathing vertebrates the 

 seat of the sense of smell is in the nostrils; in man it is 

 especially that part of the mucous lining of the nasal 

 cavity which we call the "olfactory region" (the upper- 

 most part of the nasal dividing wall, the superior and 

 middle meatus). It is necessary for a sensation of smell 



3^^ 



