320 DR. GADOW ON THE ANATOMY OF PTEROCLES. [Mar. 21, 
passes between the two principal branches of the ischiadic 
nerve, and is supported by the descending tendon of the m. 
semitendinosus =m. caudee ilio-flexorius. 
B. This head is the larger of the two, and is the most super- 
ficial one at the hinder and external aspect of the leg, as it 
arises from the external condyle of the femur. The “tendo 
communis”’ of these four heads is inserted into the hinder 
margin of the tarso-metatarsal bone, but principally into the 
tibial and median margin. 
The m. extensor digitorum communis appears after the removal of 
the superficial peroneal and of the tibialis muscle, being completely 
covered by the latter. It arises from the anterior plane of the head 
and neck of the tibia; its tendon passes through the transverse liga- 
ment and the bony bridge just above the intertarsal joint ; it then 
runs down on the anterior surface of the metatarsal bone, and sends 
a tendon to the dorsal part of the bases of the phalanges of the 
three front toes. The mode of splitting up of the common tendon 
into the special tendons and of their insertion varies much. 
M. perforatus digiti 11.—This muscle appears after the removal 
of the most superficial of the flexor muscles on the outer side of the 
leg. It comes with fleshy fibres from the ligam. fem. tibiale 
externum and from the hinder part of the neck of the tibia. Its 
long and slender tendon, after crossing the legs, passes right through 
the susceptaculum in the middle of the hinder aspect of the inter- 
tarsal joint, where it lies deeper than all the other tendons. It is 
inserted into the ventral side of the phalanges 11. et m1. digiti 11. 
M. perforatus digiti 111. consists of two very fleshy heads. The 
outer one is completely fused with that of the m. perforatus dig. 11. ; 
it arises partly from the external condyle of the femur and from the 
tendinous loop; one part of this head forms the continuation of the 
tendon of the ambiens muscle. The inner head arises with a distinct 
tendon from the hinder aspect of the middle part of the intercondy- 
loid region. 
The combined tendon of the whole muscle, when passing over the 
intertarsal joint, is quite flat, and lies between the susceptaculum and 
the broad tendon of the gastrocnemius muscle. Thus in this region 
it is the most superficial of all the flexor tendons. At the middle 
of the metatarsal bone the tendon gives off a slip to that of the m. 
perforans et perforatus dig. m1. 
M. flex. perforatus dig. 1v.—Its thick belly arises from the hinder 
aspect of the external condyle of the femur and from the intercon- 
dyloid region. Its tendon, simply covered by the tendo Achillis, 
passes as the most superficial one over the joint and is inserted into 
the basis phal. 11. dig. rv. 
The m. flex. perforans et perforatus dig. 111. arises with a long 
slender head together with the m. perforatus dig. 111. and with the 
m. perforatus dig. 11.; its tendon sends a slip to that of the m. per- 
foratus, which it also perforates, and is inserted into the bas. phal. 
1. et 111. dig. 111.; on the other hand, this tendon is pierced by that 
of the m. flexor profundus. 
