280 



THE SPECIAL SENSES. 



The distinction made by these authors between the cutaneous 

 and deep sensations, especially between the cutaneous and deep 

 sensations of pressure, is very important and must be borne in mind 

 in all studies of supposed anesthetic areas of skin. Whether the 

 distinction made by them between protopathic and epicritic sensi- 

 bility will be established by further observations is at present an 

 open question. Two other sets of observers* have used their 

 method of study, namely, the section and regeneration of a cu- 

 taneous nerve in man; but, unfortunately, they do not corroborate 



Fig. 119. Representation of the distribution of cold and warm spots on the volar 

 surface of forearm in a space 2 cms. by 4 cms. The red dots represent the cold spots as 

 tested at a temperature of 10 C. The black dots represent the warm spots as tested at a 

 temperature of 41 to 48 C. 



the findings of Head and Rivers in regard to the different qualities of 

 sensation designated under the terms "epicri tic" and "protopathic." 

 The Punctiform Distribution of the Cutaneous Senses. A 

 most interesting fact in regard to the cutaneous senses is that 

 they are not distributed uniformly over the whole skin, but are 

 present in discrete points or spots. This fact was first clearly 

 established by Blix,f although it was discovered independently 

 by Goldscheider and in this country by Donaldson. These ob- 

 servers paid attention chiefly to the warm and cold spots. The 



