Zoological Society. 63 



the vasti and crunvus are much weaker and thinner, and are evi- 

 dently little adapted to support the thigh and trunk upon the tibia. 

 The psoas ma<rnus and iliaciis internus are, on account of the form 

 of the pelvis, proportionally longer muscles than in man. Beneath 

 them exists a small distinct muscle passing from the fore part ot the 

 ilium over and attached to the capsule of the hip-jomt, to be inserted 

 into the root of the trochaiiter minor. This muscle is not found m the 

 Chiippau-ee The pectineus is a narrower muscle than m man, and 

 give^ off~in the Chimpanzee, a small slip, which is contmued under 

 The femoral vessels and outwards to the origm of the sartor ms. ihe 

 aracilis is a very powerful muscle in the Orang, but is comparatively 

 of less bulk in the Chimpanzee, in which it is inserted beneath the 

 sarforius. On this muscle being removed, a number of others appear 

 passincr from the pelvis to the inner part of the thigh, among which 

 it is dffficult to select those which are precisely analogous to the 

 muscles in the corresponding region of the human subject. Mr. 

 Owen, however, distinguished the adductor longus ; an accessory 

 adductor arising from the upper part of the symphysis pubis ; the 

 adductor brevis ; and the adductor magnus. 



The gastrocnemius preserves nearly a uniform thickness and 

 breadth throughout its course, and is continued fleshy down to the 

 OS calcis: it has no sesan.oid bone, as possessed by some monkeys 

 Ce g. Macacus cynomolgus, Lacep.)> at either of its origins, ihe 

 soleus has onlv one origin, and is continued fleshy to the os calcis. 

 The tendon of the popliteus contains, behind the knee-joint, a tibro- 

 cartilaainous sesamoid body, which was noticed by Camper, who 

 states That it exists also in baboons, dogs, cats, &c. : this body, how- 

 ever, is not found in the Chimpanzee. _ 



In the Orano- JJtan there are some important difterences in the 

 disposition of t1ie flexors of the toes, as compared with the Chim- 

 nan-ee and inferior Simice ; thus the muscle analogous to ihe/e.ror 

 lon<rus poinds pedis sends no tendon whatever to the thumb of the 

 fool and its origin is extended above the knee-joint in a manner 

 analogous to the flexor sublimis in the upper extremity. It has two 

 origins, one from the outer condyle in common with the gastro- 

 cnemius internus, the other from the head of the Jibida, and is con- 

 tinued down the posterior part of that bone and the interosseous 

 li.rament to within an inch of the tarsus ; under which it passes 

 throuMi abroad svnovial sheath, deeper seated than, and external to, 

 the flexor longus digitorum ; becoming tendinous centrad, but con- 

 tinuing fleshy on the dermal aspect till it has reached the sole. 

 Tiiere it divides into two stout perforating tendons, which are in- 

 serted into the distal phalanges of the third and fourth toes Jm- 

 mediately after liie division each tendon gives origm to a iumbri- 

 calls muscle, wliicli terminates in a thin aponeurosis attached along 

 the tibial side of tiie proximal phalanges o( the thud and fourth toes. 

 The flexor longus digitorum pedis arises as in liie human subject, 

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

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

 tendons. The lumbricalis terminates in the middle tendon of the 



three. 



