416 Harris Hawthorne Wilder, 



enwrap and conceal tlie others, as described in the case of the 

 ulnar extensor of the forearm. The insertion includes the entire 

 free niargin of the fibula, and is continued along the fibular margin 

 of the fibulare-intermedinm. A bündle of the shorter flbers Covers 

 the proximal part of the dorsal aspect of the fibula and forms an 

 area of insertion that terminates in an oblique line across the 

 middle of the shaft. 



Mm. extensor es breves (eb 2—5). These small muscles 

 are fonr in number, one for each digit, and appear superficially as 

 oval beilies, interdigitating with the slips of the femorometatarsalis. 

 They arise form the distal margins of the tarsalia that correspond 

 to the digits to which they belong, tarsale 4 + 5 giving rise to two, 

 as would be expected. The bellies are continued into long, narrow 

 tendons, but partially diiferentiated from the aponeurosis that 

 Covers the dorsal surface of the digits, and appear as thickened 

 stripes along the middle of the toes. These insert into the bases 

 of the terminal phalanges. 



The relation of tbese Short extensors and their partially differentiated 

 tendons to the femorometatarsalis, and the possibility of the formation of 

 an extensor communis from the union of both sets of muscles, has been 

 fully discussed under the two muscles, humerometacarpalis and femoro- 

 metatarsalis, and under the extensores breves of the arm. 



2. Volar aspect of leg and foot. 



Plantar fascia (fp). The muscles of the volar surface of 

 the lower leg and foot are covered superficially by a fascia which, 

 distal to about the middle of the leg, becomes thick and opaque, 

 concealing all subjacent parts. This latter portion is the plantar 

 fascia proper, and extends distally as a continuous sheet from the 

 distal margin of. M. plantaris superficialis, of which it forms an 

 aponeurotic continuation. At about the baseofthemetatarsalsitdivides 

 into four slips, which gradually narrow and lie along the volar 

 aspects of the four digits, inserting into the bases of the terminal 

 phalanges. These tendon-like slips are tied down by ligaments 

 opposite the metatarso-phalangeal joints, and, in the case of digit IV, 

 also opposite the extra Joint between phalanges 1 and 2. While 

 opposite the row of tarsalia, and shortly before its division into 

 the four digital slips, the plantar fascia becomes firmly fastened to 

 the distal border of these bones, and the crescentic partition of 

 firm connective tissue thus formed, and the surface of the fascia 



