132 THE OSTEOLOGY AND MYOLOGY 



at the termination of the vastus, lies upon the soleus, and blends with the latter far above 

 where the same becomes tendinous ; it is the superior and posterior, or superficial portion. 

 Just below, and a little to the outer or fibular side, lies another smaller mass, taking origin 

 exclusively from the surface of the soleus, with which it blends below. The soleus proper 

 consists of two heads, the most posterior or superficial of which arises from the fibular sesa- 

 moid fibella and lateral knee joint ligament, and slightly from the external condyle ; the 

 most deep seated from the head of the fibula, between the peroneus longus and long digital 

 flexor. The compound muscle, so constituted, forms a great protuberance, deep antero-pos- 

 teriorly, narrow from side to side ; tapering gradually as it descends, becoming tendinous a 

 little below the middle of the leg, and then soon crossing inside (in front of) the tendon of 

 the preceding, to be inserted into the inner lower corner of the tuberosity of the os calcis. 

 Thus there are two perl'ectly distinct tendones achillis, without counting the plantaris as one. 

 This muscle has no connection with the tibia. Is it likely that the politteus (no traces of 

 which as a distinct muscle can be found) is represented by one of the divisions described ? 



Plantaris. Tensor fascicB plantaris. — (Fig. 34, d.) Well developed, of large size, 

 arising from the fibular fabella, distinct from the foregoing. It is a flattened muscle, be- 

 coming tendinous at the lower third of the leg. Its tendon passes along the inner border 

 of the inner tendo achillis, lying upon the tendon of the flexor longus digitorum. It begins 

 to become fiiscial above the heel, passes over the latter just inside of the os calcis, and is 

 continued along the sole as the plantar fascia. 



Flexor communis digitorum longus. — (Fig. 34, g, g, g, its muscular part, and fig. 35, a, its 

 tendons.) This is the flexor perforans seu profundus, as proved no less by its own physical 

 characters than by the relation that the short flexor of the toes bears to it. It lies upon 

 the fibular side of the leg — exchanging places with its flexor longus pollicis, as far as 

 anthropotomical relations are concerned. It is much the largest of the four muscles con- 

 stituting the deep layer of the posterior set. It is bipinnatifid, and has a groove along its 

 inner aspect in which the fibula lies partly embedded. It arises from the head and nearly 

 all the shaft of the bone, blended somewhat above and on the inner side with the tibialis 

 posticus. Just above the heel it becomes tendinous; a fibrous e.Kpansion of the tendon runs 

 up the surf\ice of the muscular part nearly to the head. The tendon — very short and much 

 flattened — passes the heel in the deep notch between the os calcis and inner malleolus ; and 

 just at the middle of the sole disengages four tendons, that at once diverge to the four 

 lesser toes. The conjoined tendon cannot be subdivided higher up ; it is a single dense 

 fibrous band. Each tendon lies upon the under surface of a toe, enclosed in a sort of sheath 

 formed by lateral expansion of the tendon of the musclfe next to be described, at length 

 perforates the latter, and finally is inserted into the base of the distal phalanx. These ten- 

 dons are quite stout, and flattened ; each, in passing the continuity of the medial phalanx, 

 is closely bound down by a distinct, strong, transverse, fibrous band. Before its division 

 the large common tendon is joined by the tendons of the flexor longus pollicis, and the 

 flexor brevis pollicis obliquus. The accessory muscles (lumbricales) are described further on. 



Flexor digitorum " brevis." Flexor suhlimis s. perforatus. — The homotypy of this 

 muscle with the corresponding one of the hand, is not only proved by its relations to the 

 long or profound flexor of the foot, but is further carried out, in a very interesting way, by 

 the fact that, instead of being confined to the sole, as in anthropotomy, it arises above the 

 heel, part way up the leg. The occasion for this prolongation of the muscle above the heel 

 may be of a part with that which determined the similar extension of its antagonist, the 



