230 Zoological Society. 



attached to the bicipital pulley : it continues to derive a thin stratum 

 of flesh jj^ fibres from the fascia covering the anterior surface of the 

 muscles of the leg : the fleshy fibres terminate half-way down the 

 leg in a flattened tendon, which pierces the tendon of the first per- 

 foratus 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 pedis 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 : this 

 tendon moreover receives the long slender tendon sent off" 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 carneous part. Before the ^e.ror digitorum is joined 

 by the tendon of the pectineus, it subdivides posteriorly into four 

 muscular fasciculi : the anterior division receives principally the above 

 tendon. The muscle becomes wholly tendinous two-thirds down the 

 leg ; its tendon passes through the posterior part of the pulley of the 

 gastrocnemius, and expands as it passes along the metatarsus : a thick 

 ligamentous substance is developed in it, opposite the joint of the 

 proximal phalanx of the second toe, into the sides of which it is 

 inserted, dividing for that purpose, and giving passage to the two 

 other flexor tendons of that toe. The second portion of the present 

 muscle terminates in a tendon situated behind the preceding, which 

 passes through a distinct sheath behind the tarsal joint, expands 

 into a sesamoid fibro- cartilage beneath the corresponding expansion 

 of the previous tendon, which it perforates, and then becomes itself 

 the perforated tendon of the second phalanx of the second toe, in the 

 sides of which it is inserted. The third portion of this muscle ends 

 in a somewhat smaller tendon than the preceding. The fourth and 

 most posterior portion soon becomes a distinct muscle ; its fleshy 

 fibres cease on the inner side, one-fourth down the leg, but on the 

 outside they are continued three-fourths down the leg : its tendon 

 passes through the gastrocnemial pulley behind the ankle-joint, and 

 divides to form a sheath for the first perforatus of the fourth toe ; 

 it is then joined by a tendon passing through a pulley across the ex- 

 ternal malleolus, and finally becomes the perforated tendon of the 

 first metacarpal bone of the middle or third toe. 



Pectineus {Rectus anticus femoris of Meckel). — This is a long, 

 thin, narrow strip of muscle arising from the spine of the pubis, ante- 

 rior to the acetabulum, and passing straight down the inner side of 

 the thigh ; it degenerates into a small round tendon near the knee, 

 which tendon traverses a pulley, formed by an oblique perforation in 

 the strong rotular tendon of the extensors of the leg, and thus pass- 

 ing across the knee-joint to the outer side of the leg, finally expands, 

 and is lost in the flexor perforatus digitorum last described. It is this 

 muscle which causes the toes to be bent when the knee is bent. 



