71 



extensor longus digitorum; it is inserted into the base of the phalanx : 

 (the female specimen that was dissected had only one phalanx to the 

 hinder thumb). The digitorum tensor longus has the usual origin, 

 continues fleshy to the ankle-joint, there divides into three tendons, 

 which diverge at the middle of the foot, and are attached to the 

 third, fourth and fifth toes ; each tendon expanding into a sheath 

 over the back part of the phalanges. 



The extensor brevis digitorum pedis arises from the os calcis, and 

 divides into three portions ; the strongest of which gives two ten- 

 dons to the second toe, one being inserted at the base of the proximal 

 phalanx, the other expanding over the second and distal phalanges 

 like the tendons of the extensor longus. The remaining portions go 

 to the fibular aspect of the third and fourth toes. 



The peroneus longus and brevis arise together from the outer, fore, 

 and back part of the Jibula ; on the latter aspect they are in con- 

 nection with the Jlexor longus pollicis. The tendon of the peroneus 

 brevis is inserted into the base of the metatarsal bone of the little 

 toe. The tendon of the peroneus longus passes under the cuboid 

 bone, without the interposition of a sesamoid bone, crosses the foot, 

 and is implanted into the metatarsal bone of the thumb of the 

 hinder hand, of which, as far as the structure of the articulation 

 will permit, it is o. jlexor. There is no peroneus tertius. 



The thumb is very short, consisting, in the female at least, 

 of only two bones, set on at right angles to the foot, and at a 

 great distance from the toes. In this part, however, the power of 

 a considerable muscular apparatus is concentrated. Receiving no 

 tendon from the ^exor longus pollicis, it is rendered more inde- 

 pendent in its actions; not being necessarily flexed, except in the 

 action which turns down that side of the foot to which it is attached, 

 and by which it is brought closer to the object to be seized. On 

 the sole of the foot we find an abductor and an adductor pollicis, both 

 powerful muscles inserted at very open angles into the phalanx } 

 which, when they cooperate in their contraction, they must draw 

 down in the diagonal with great force. Between these are situated 

 two more direct flexors, constituting what is usually termed the 

 Jlexor brevis pollicis. 



The space between these muscles, which in man and the Chim- 

 panzee is filled by the tendon of the Jlexor longus pollicis, in the 

 Orang Utan is occupied by a small peculiar muscle which arises 

 from the metatarsal bone, and is inserted into the phalanx. In a 

 young male Orang that had two phalanges the Jlexor brevis was 

 inserted partly into the second phalanx. The e.Ttensor brevis pol- 

 licis arises from the os navicidare and os calcis, and is inserted into 

 the base of the proximal phalanx, when there are two. 



On the dorsum of the foot may also be observed interossei ex- 

 terni of a penniform shape ; they are attached to the fibular aspect 

 of the Y)X oyiimaX johalanges of the toes. There was also an adductor 

 minimi digiti, and interossei interni, but not any trace of transver- 

 salis pedis. 



Mr. Owen concluded his observations with some remarks on the 



