70 



mediately after the division each tendon gives origin to a lumbri- 

 calls muscle, which terminates in a thin aponeurosis attached along 

 the tibial side of the proximal phalanges of the third and fourth toes. 



The Jlexoj- longus digitorum pedis arises as in the human subject, 

 but continues fleshy till it has passed under the abductor pollicis ; 

 it then gives orijjin to a lumbricalis muscle, and divides into three 

 tendons. The lumbricalis terminates in the middle tendon of the 

 three. The innermost or first tendon goes to the distal phalanx of 

 the second toe; it also gives rise to -a lumbricalis, which is inserted 

 into the tibial side of the proximal phalanx of the same toe. The 

 second tendon, after receiving the insertion of the lumbricalis before 

 mentioned, goes to form the perforated tendon of the fourth toe. 

 The third or outer tendon is inserted into the distal phalanx of the 

 fifth toe, and also gives origin to a lumbricalis, which terminates in 

 the tibial side of the proximal phalanx of the same toe. 



Ihejlexor brevis digitorum pedis arises from the posterior part of 

 the OS calcis, its fibres passing transversely over the insertion of the 

 tendo AchiUis. At about two inches from its origin it gives off a small 

 tendon, which is inserted into ihe ?.econA phalanx of the second toe. 

 It then continues fleshy for an inch further, and terminates in the 

 perforated tendon of the third toe. 



Thus all the toes from the second outwards, have zjlexor tendon 

 inserted into the distal phalanx : they have also alumbricalis tendon 

 attached to the proximal phala7ix, and the second, third, and fourth 

 have tendons inserted into the middle phala?ix. As each perforating 

 tendon gives origin to the lumbricalis muscle of its respective fin- 

 ger, these not only assist in the flexion, but act as guys on the 

 tendons, from which they originate, preventing them from starting 

 from the long concavity of the sole over which they travel ; they 

 also afford a variety of independent motions to the fingers. The 

 tibialis posticus has the usual origin; its tendon passes along a dis- 

 tinct sheath close by the internal malleolus ; it is inserted into the os 

 cuneiforme internum. The tendon has no sesamoid bone where it 

 passes over the astragalus. In the Chimpanzee it is inserted into the 

 OS navicidare. 



The muscles in front of the leg are covered with a strong Jascla, 

 into which the tendons of the semitendinosus and biceps are inserted; 

 it afibrds origins for the muscles situated beneath it, and becomes 

 very strong at the ankle, binding down and forming sheaths for 

 the several tendons. The tibialis anticus arises from the anterior 

 inner and posterior aspects of the tibia, embracing it, as it were, and 

 giving the appearance of a rickety convexity to the leg ; it passes 

 over the malleolus interims posterior to the centre of motion, and is 

 consequently an extensor of the foot; it also turns the sole inwsrds. 

 In close connection with this arises another muscle, not found in 

 man ; it becomes tendinous about three-fourths down the leg, and 

 is inserted into the base of the metatarsal bone of the thumb, which 

 it extends : this muscle is found in the Chimpanzee, and also, ac- 

 cording to M. Cuvier, in the inferior Simice. The extensor longus 

 pollicis makes its appearance as usual between the tibialis anticus and 



