The Journal of 



Comparative Neurology and Psychology 



Volume XIX June, 1909 Number 3 



ON SENSATIONS FOLLOWING NERVE DIVISION. 



BY 



SHEPHERD IVORY FRANZ. 

 From the Laboratories of the Qovernment Hospital for the Insane, 



Washington, D. O. 



With Seven Figures. 



II. The Sensibility of the Hairs. 



Examinations of the sensibility of the skin from the standpoint 

 of punctate sensibility indicate that the hairs are closely associated 

 with those points that are stimulated by pressures and that react 

 by giving a sensation of pressure or touch. The hairs are assumed 

 to have a form of sensibility allied to or the same as that of neigh- 

 boring parts sensitive to touches or pressures, although on thi's point 

 most authors are silent.^ The experiments carried out by Head and 

 Sherren indicate, however, that the hairs are independently sensitive 

 to stimuli and that they react in a different manner than do the so- 

 called pressure points. Numerous observations in cases of nerve 

 lesions show that the sensations evoked by stroking or pulling the 

 hairs differ from those of pressure and touch of the skin. For 

 example, in an individual whose radial nerve has been cut the parts 



'That this is probably not so is indicated by recent studies of the nerve 

 endings (presumably sensory) in or near the hair bulbs of "touch" hairs in 

 animals. The structures which have been found are different to those on 

 hairless parts endowed with sensibility to touch and pressure. 



The Journal of CowrARATivB Neurologt and Fsycholooy. — Vol. XIX, No. 3. 



