106 ANATOMY OF VERTEBRATES. 



converge, receive the tendinous slip from the femoral portion, and 

 end on the inner side of the muscle in a strong flattened tendon, 

 about two-thirds down the leg : this joins the tendgn of the gas- 

 trocnemius externus and is inserted as described above. 



The soleus ^ is a slender flattened muscle arising from the 

 posterior part of the head of the tibia, the tendon of which joins 

 that of the gastrocnemius internus, behind the tarsal joint. 



The flexor perforans digitorum ^ lies immediately anterior to 

 the external gastrocnemius ; it arises fleshy from the outer con- 

 dyle of the femur, below the tendinous origin of that muscle, and 

 terminates in a slender flat tendon half-way down the leg. Its 

 tendon, fig. 35, 5i, glides behind the tarsal joint through the 

 sheath of the gastrocnemius, expands beneath the metatarsus and 

 bifurcates, sending its smallest division to the inner toe, ib. 5 2, and 

 its larger one to blend with the tendon of the peroneus medius. 



Flexor perforatus of the outer toe.^ This arises by very short 

 tendons from the proximal end of the fibula, and from the liga- 

 ment forming the bicipital pulley ; it continues to derive a thin 

 stratum of fleshy fibres from the fascia covering the anterior sur- 

 face of the muscles of the leg : the fleshy fibres terminate half- 

 way dowm the leg in a flattened tendon, which, after entering the 

 gastrocnemial sheath, pierces the tendon of the first perforatus of 

 the middle toe, then runs forward to the outer toe, expands into a 

 thick ligamentous substance beneath the proximal phalanx, and 

 sends off two tendinous attachments on each side, one to the 

 proximal, the other to the second phalanx, and is continued to be 

 finally inserted into both sides of the third phalanx. 



Flexor perforatus digitorum ^ is the strongest of the three ; it 

 arises fleshy from the posterior part of the distal extremity of the 

 femur, above the external condyle, and also by a distinct flattened 

 tendon, one inch in length, from the proximal end of the tibia, 

 fig. 35, 50 : this tendon, moreover, receives the long slender 

 tendon, ib. 4i, sent oif obliquely across the front of the knee- 

 joint from the pectineus, by which its origin is extended to the 

 pelvis. This accessory tendon perforates the inner fleshy surface 

 of the muscle, and is finally lost about half-way down the car- 

 neous part. Before the flexor perforatus is joined by the tendon 

 of the pectineus, it subdivides posteriorly into four muscular 

 fasciculi. The anterior division receives principally the above 

 tendon, and this division of the muscle becomes wholly tendinous 

 two-thirds down the leg ; its tendon passes through the posterior 



' xr. vol. iii. pi. 35, S. - Ib. pis. 31, 32, 35, 1. ^ ^o. pis. 31, 32, 35, 2. 



^ Ib. pis. 32, 35, 3, 4, 5, 6. 



