HENSEL, H. 
SUMMARY 
In the external skin of the cat, no specific cold or warm fibers 
seem to exist within the group of myelinated A fibers but only non- 
specific receptors excited by pressure and cooling. However, 
numerous specific cold and warm receptors have been found with 
non-myelinated C fibers, the conduction velocity of which was be- 
tween 0.5 and 1.5 m/sec. The quantitative sensitivity of these re- 
ceptors corresponded well with the threshold for subjective 
temperaure sensations in man. 
In human subjects, only one specific cold fiber has been found 
as yet in the A group, whereas several A fibers responded to pres- 
sure as well as to cooling. The latter probably cause a mechanical 
sensation. 
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