INNERVATION OF THE HUMAN SKLN 219 



Table I. — Distribution of Touch Corpuscles : — 



In the deep connective tissue of the dermis there are : — 

 In the thumb about 70. 



,, ,, index finger 105. 



„ ,, middle finger 60. 



,, ,, whole hand 500. 



They are numerous over finger joints and front of elbow joint. 



In all 530 about the joints of the upper extremity. 

 317 about those of the lower extremity. 



Table II. — (From Schafer's Text Book of Physiology) : — 



Average of Meissner's corpuscles to each square millimetre, 

 which is approximately one five hundredth part of a 

 square inch : — 

 Palmar surface of distal phalanx of index finger 21 



Palmar surface of second phalanx of index finger 8 



Palmar surface of first phalanx of index finger 4 



Palmar surface of metacarpus of little finger 2 



Plantar surface of distal phalanx of great toe 7 



Middle of sole of foot 2 



Flexor surface of forearm in each sq. mm. 1 



Distal end of flexor surface of forearm in each sq. mm. : — 

 1 to each 6 sq. mm. approximately. 



* Absent from the cornea, and conjunctiva of the upper eyelid 

 and from the glans penis. 



Table III. — Distribution of Touch Spots : — 



These must be distinguished, of course, from the touch 

 corpuscles of the preceding list and the subjective element 

 in the study of them must be borne in mind. 



If an area, as of the calf of the leg, be prepared, by cutting 

 short the small hairs, and examined, it is found that there 

 are about 15 touch spots in each square centimetre, which 

 is about one-fifth of a square inch. 



In another area so treated the hairs are counted and the following 

 result is given :— 



1. On the dorsal surface of the forearm 78 touch spots are 

 found in an area containing 15 hairs. 



2. On the flexor surface of the forearm 147 touch spots are 

 found in an area containing 22 haiis. 



3. On the scalp 66 touch spots are found in an area containing 

 38 hairs. 



