360 DR. C. F. SONNTAG ON THE ANATOMY, 



peroneal intermuscular septum. The flat belly gradnally expands 

 till it reaches a point an inch above the calcaneus. The superficial 

 part of the central portion becomes tendinous in the lower third, 

 and is joined by the gastrocnemius to form the tendo Achillis. 

 The tendo Achillis is inserted into the middle of the posterior 

 aspect of the os calcis. It is separated from the upper part of the 

 bone by a bursa and a pad of fat. 



Tlie popUteus is double, but its origins and insertions are all in 

 contact to form linear attachments. The proximal fibres rise 

 from the posterior aspect of the capsule of the knee-joint internal 

 to the outer head of the gastrocnemius. The distal fibres arise as 

 in Man. The proximal pai't is inserted into the vertical line on 

 the posterior aspect of the internal tibial condyle. The distal 

 part goes to the oblique popliteal line, the posterior border of the 

 subcutaneous area, the internal condyle and a curved line run- 

 ning round the internal condyle. 



The flexor longus diffitorum arises from the popliteal line and 

 its medial continuation downwards to within half an inch of the 

 inner malleolus, and from the septum between it and the tibialis 

 posticus. The tendon passes round the back of the internal 

 malleolus and under the inner end of the internal annular 

 ligament. It crosses to the lateral side of the sole of the foot 

 and is joined by the tendon of the accessorius and a. slip from the 

 flexor longus hallucis. A small slip runs to the la,teral tendon of 

 the flexor brevis digitorum. Then it divides into five tendons 

 for the four inner toes, the fourth receiving two. The first and 

 second tendons, to the second and third toes, are accompanied 

 superficially by tendons of the flexor brevis. In the case of the 

 fourth toe the superficial tendon of the longus replaces the 

 tendon of the brevis. The tendons are inserted as in Man. 

 The tendon to the little toe is attached by a broad vinculum to 

 the body of the proximal phalanx, by a triangular vinculum to 

 the second phalanx and is inserted into the base of the terminal 

 phalanx. The fiexor sheaths are as in Man. 



The /o-Jtr lumhricales pass to the inner parts of the dorsal 

 expansions of the extensor tendons of tho four inner toes. 



The accessorius is very small and has only the external head 

 which runs from the outer edge of the calcaneus and the long 

 plantar ligament to the outer aspect of the flexor longus 

 digitorum. 



The flexor longus hallucis arises from the lower part of the 

 posterior aspect of the head of the fibula, from the posterior 

 surface of the fibula almost to the malleolus, from the fascia 

 between it and the tibialis posticus, from the posterior peroneal 

 intermuscular septum, the lower part of the interosseous mem- 

 brane and slightly from the tibia near the interosseous membrane. 

 The tendon is inserted into the base of the terminal phalanx of 

 the hallux, and the capsule of the interphalangeal joint. In the 

 sole a large tendon connects it to the flexor longus digitorum. 

 It has a flexor sheath. The tendon runs through a trochlea 

 attached to the base of the flr-st metatarsal. 



