394 THE SENSORIAL FUNCTIONS. 



of velvet. In the fore part of the human tongue 

 these papillae are visible even to the naked eye ; 

 and especially in certain morbid conditions of 

 the organ.* They are of different kinds ; but 

 it is only those which are of a conical shape 

 that are the seat of taste. If these papillae be 

 touched with a fluid, which has a strong taste, 

 such as vinegar, applied by means of a camel- 

 hair pencil, they will be seen to become elon- 

 gated by the action of the stimulus ; an effect 

 which probably always accompanies the percep- 

 tion of taste. 



The primary use of this sense, the organ of 

 which is placed at the entrance of the alimen- 

 tary canal, is evidently to guide animals in the 

 choice of their food, and to warn them of the 

 introduction of a noxious substance into the 

 stomach. With respect to the human species, 

 this use has been, in the present state of society, 

 superseded by many acquired tastes, whicli have 

 supplanted those originally given to us by na- 

 ture ; but in the inferior animals it still retains 

 its primitive office, and is a sense of great im- 

 portance to the safety and welfare of the indivi- 



* This is particularly the case in scarlatina, in the early stage 

 of which disease they are elongated, and become of a bright red 

 colour, from their minute blood-vessels being distended with 

 blood. As the fever subsides the points of the papillae collapse, 

 and acquire a brown hue; giving rise to the appearance known 

 by the name of the strawberry tongue. 



