164 THE SENSE OF TOUCH IN ANIMALS 



the surface of the skin, to which papillary ridges and their equiva- 

 lents in lower forms easily lend themselves. An important 

 manifestation of the tactile sense is that by which it suppUes 

 to the cerebellum, one of the four afferent impressions necessary 

 for " keeping it informed of the position of the body in space." 

 Further reference to this function will be made shortly. 



Uses of the Sense of Touch. — It remains to be asked of what use 

 to the animal in the course of its hfe are these tactile structures 

 and the tactile sense ? To answer this question, one must first 

 consider the tactile sense of the hand and foot of man as known 

 better to us than those of any lower animal, thus proceeding 

 from the well known to the less known. 



The Hand of Man. — From the days of eohthic man, up to a 

 comparatively recent period, the basal element of his progress in 

 civihsation has been an increasing skill in the use of implements. 

 This is so much so, that the early epochs of his long reign over 

 the earth have derived their titles from the nature of his imple- 

 ments ; as the Stone Age, old and new, the Iron Age and the 

 Age of Bronze. It is easy to understand that in such a develop- 

 ment of mechanical apphances as these titles indicate, the sense 

 of touch has played an extremely important part. 



This making of implements constituted a large part of his 

 armoury in early times which equipped him in his struggle for 

 mastery with the lower animals, and of itself, it divided him by 

 a great gulf from these his enemies or rivals. Little imagination 

 is needed to enable one to understand how his acute sense of 

 touch became a useful servant to his developing brain, as he 

 learned to distinguish between such substances as stone of 

 various kinds, wood of different structures, and metals, and to 

 handle both the tools he made from them as well as the raw 

 materials. Implements employed for the purpose of war against 

 the lower animals became, in due time, supplemented by those 

 belonging to the peaceful arts. In the construction of the imple- 

 ments of the chase, of agriculture, of domestic arts and finally 

 of scientific apparatus, an immense field is opened to the more 

 or less skilful apph cation of the sense of touch. Between the 

 tactile structures in the skin of early man, who chipped rough 



