THE SENSE OF TOUCH 393 



over the last phalanx is particularly well supplied 

 with touch spots localized in the corpuscles of Meissner, 

 thus rendering the tip of the finger more acute in the 

 sense of touch. It must be remembered that when 

 the pressure and temperature (extremes of heat or 

 cold) of an object are too severe the sense of touch 

 and temperature is lost in the sense of pain. The 

 sense of touch is replaced by the sense of pain when 

 the skin is bruised or burned, so that the epidermis 

 is destroyed, leaving the nerves too exposed. 



The sense of pressure is the variety of the touch 

 sense which is based on the fact that, when pressure is 

 brought to bear along with touching an object, the 

 pressure of the object coming in contact with the skin 

 must reach a certain intensity before the sensation of 

 weight will be appreciated, and permit the individual 

 to determine the amount of the pressure, and gauge 

 the comparative pressure of low weights. 



The Sense of Place. Is .based on the fact that when 

 a stimulus touches any portion of the skin the sensa- 

 tion caused thereby is, under normal conditions, 

 always referred to the place stimulated. This is 

 always the case, whether the place of stimulation is 

 at two points near or distant from each other on the 

 same side of the body, or the corresponding place 

 on the opposite side. These areas for the localization 

 of sensations are usually arranged in circles throughout 

 the surface of the skin. 



The Temperature Sense. This is supposed to be 

 due to the presence in the skin of special nerve-endings 

 which give rise to sensations of heat and cold, and 

 are different from each other, as well as from those 

 end-organs which give rise to sensations of touch. 

 It has been proved by investigation that throughout 

 the surface of the skin there are spots, called heat and 

 cold spots, which if stimulated give rise to sensations 

 of heat and cold. Each spot responds to only one 

 kind of stimulus, thus a warm object applied to the 



