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VETEKINAKY PHYSIOLOGY 



such light contact and to slight differences of temperature, 

 giving sensations of warmth and coldness as opposed to the 

 previous sensations of hot and cold. This he terms Epieritie 

 Sensibility. 



He discovered a small area on his hand in which the 

 epicritic sense was not lost but the protopathic sense was 

 lost. Light touch and differences of temperature between 36 

 and 45 C. were appreciated, but the difference between water at 

 50 C. and ice was not felt. 



He concludes from this and from the different rate of 

 regeneration that the two sets of nerves are independent. 



Sp.C. 



SK. 



Fig. 50. To show the arrangement of Epicritic, Protopathic, and Deep-ingoing 

 Fibres in their distribution, and in their course in peripheral nerves and 

 in the plexuses ; f j Epicritic Fibres ; - ^^ Protopathic Fibres ; 

 -o-o-o Deep Fibres. (See text.) 



He further finds, from the study of cases of nerve section, 

 that division of a peripheral nerve leaves sharply-defined areas 

 of loss of epicritic sense, but great overlaps in the protopathic 

 sense. On the other hand, when a cord of the brachial plexus 

 is divided, the area showing loss of protopathic sense is more 

 sharply defined. When a series of posterior roots are cut, 

 loss of protopathic and epicritic sensibility correspond. He 

 concludes that the posterior roots are the units for proto- 



