THE MUSCLES OF THE LOWER EXTREMITY. 215 



joint, and is inserted into the anterior part of the 

 proximal end of the tarso-metatarsal bone, sending off 

 a small tendinous slip to the aponeurosis covering the 

 extensor tendons of the toes, and a strong tendon 

 which joins the fibular side of the tendon of the ex- 

 tensor long us dig itorum" (Anat. of Verts., vol. ii. p. 108). 



In man, we remember, the tibialis anticus is a direct 

 flexor of the tarsus upon the leg. 



113. The extensor longus digitorum 1 (Fig. 51) arises 

 fleshy from the under edge of the procnemial ridge or 

 crest of the tibia, its mesial side, and from a limited 

 area of the contiguous surface of the shaft of the bone. 

 Its fibres pass down on the iuterno-anterior aspect of 

 the tibial shaft, as a long, slender, fusiform muscle. 

 At the lower third of the bone its strong tendon sup- 

 plants the carneous portion, and gradually coming to 

 the middle line, passes under the bony bridge just above 

 the condyles in front. Emerging from this, it passes 

 over the front of the ankle-joint, being bound down in 

 this situation by a firm fascia. It is now slightly 



1 A study of the methods of insertion of this muscle throughout 

 the Class Aves is a very interesting one, and shows it to be very 

 different in several of the groups. Gadow gives its synonymy as 

 follows : 



" 46. M. EXTENSOR DIGITORUM COMMUNIS. 



M. primus anterior pedem et digit os movens. Aldrovandi. 

 M. duodecimus circa tibiam et fibulam. Steno. 

 L'extenseur commun des doigts. Vicq d'Azyr, p. 282, No. 3. 

 Schienbeinmuskel. Merrem, p. 161, No. 5. 

 M. extensor digitorum communis. Wiedemann, p. 100. 

 Tiedemann, 308. 



,, ,, ,, Quennerstedt, p. 39. 



Neander, p. 23 ; Gadow, No. 32. 



Watson, p. 126. 

 Extensor digitorum longus. Owen, Apteryx, p. 297. 



De Man, p. 135, No. 27. 



L'extenseur commun des doigts. Gervais et Alix, p. 33 ; Alix ; 

 p. 453." 



