466 SURGICAL APPLIED ANATOMY. [Chap. XXIIL 



with nerves, being furnished with branches from no 

 less than six nerve trunks, the musculo-cutaneous, 

 the anterior tibial, the two saphenous, and the external 

 and internal plantar. 



Many Pacinian bodies are found upon these 

 cutaneous branches, and end-bulbs are met with in the 

 skin on the sole and dorsum. It must be remembered 

 that these nerves come from a considerable distance 

 (the long saphenous from the lumbar plexus, and the 

 remainder from the sacral) so that pain experienced 

 in the foot may be due to causes very remotely 

 situated. Thus, Sir B. Brodie mentions a case of 

 severe neuralgia of the foot, after each evacuation of the 

 bowels, caused by the descent and pressure of internal 

 piles. The integuments of the foot respond acutely 

 to sensations of pain, of pressure, of temperature, and 

 to certain unwonted forms of tactile impression, such 

 as tickling. Tactile sensibility, however, as measured 

 by the sethesionieter, is not acute, the dorsum of the 

 foot showing, in regard to this matter, no more sen- 

 sitiveness than does the skin of the buttock. 



Over the "tread of the foot," and especially under 

 the ball of the great toe, the peculiar affection known 

 as " perforating ulcer " is most commonly met with. 

 This ulcer occurs as an occasional symptom in certain 

 nerve maladies, and particularly in locomotor ataxy. 



The fascia; of I. lie foot and the tendons 

 about the ankle. The fasciaB on the dorsum occur 

 in two layers, a superficial one that is continued from 

 the anterior annular ligament, and a deeper placed 

 over the extensor brevis and interossei muscles. These 

 membranes are both thin and insignificant, and exercise 

 no influence from a surgical point of view. The 

 plantar fascia is divided into three parts, a central or 

 main portion which is extremely dense and powerful, 

 and two lateral expansions which are thin and 

 surgically insignificant. The outer of the two lateral 



