17 



lar possesses (Martin, ubi supra). The whole hand is remarkable 

 for its slenderness and length, by which it is beautifully adapted for 

 grasping the boughs of trees or any such objects : the fingers main- 

 tain similar proportions, one to another, to those of Man. The 

 thumb, longer than in the Chimpanzee, where it does not quite equal 

 in length the metacarpal bone of the first finger, is slender in form. 



So extraordinary is the length of the fore extremity, that the hu- 

 merus reaches to nearly the šame part of the trunk as the wrist in 

 Man, and that the fingers really ręst on the ground when the animal 

 assumes the erect ])osture. The length of the fore-arm of this ske- 

 leton, whose totai height is only about two feet, positively exceeds 

 in length that of the adult human subject, being eleven inches long. 



Never have I seen a skeleton which better illustrates the law of 

 animal mechanics, that rapidity of movement depends on the elon- 

 gation of the short arm of the lever (which every bone represents) 

 in proportion to the long arm of the šame ; or (otherwise expressed) 

 on the extent of the distance between the fulcrum and weight in 

 proportion to the distance between the fulcrum and the power. 



As respects the proportions of the fore-limbs, the Orang Utan 

 approaches the Gibbons, and retrogresses from Man more than the 

 Chimpanzee, since in the former the arms reach to the heel, in the 

 latter to about the knee-joint. 



Section IV. — Of the Hind Extremities. 



The pelvis presents us with a type far degraded from the Bimanous. 

 The hips are narrow ; the iliac bones long and flat, and their superior 

 margins do not present an are of a circle, as in Man, and indeed to 

 a certain extent in the Chimpanzee. The ischiatic bones, instead of 

 retreating far backward from the symphysis of the pubes, are nearly 

 on a plane with the iliac wings ; their inferior margins are not cir- 

 cular, as in Man, but present three sides of a lengthened parallelo- 

 gram. The symphysis of the pubic bones resembles that of Man 

 more than does that of the young Chimpanzee. 



The bones of the lower extremities are characterized, as those of 

 the pectoral limbs, by the slenderness of their form and the slightness 

 of their elevations. 



The trochanters of the femur are small ; the linea aspera absent. 

 The ligamentum teres appears to have been present, thus agreeing 

 with Man and all the Simiadee, excepting the Orang Utan. 



The tibia and fibula have rather a larger interosseous space thai^ 

 in Man, conseąuent on the bowing of the fibula. This space is large 

 in the Orang Utan (Owen, ubi supra). 



The relative proportions of the leg and fore-leg are similar to the 

 human, 



Let me here introduce a remark made on this animal by Yarrell, 

 viz. that both the upper and lower extremities are incapable of the 

 šame extension as in Man, owing to the strong facial expansion of 

 the flexor tendons passing before the elbows and behind the knee- 

 joints to be attached to the upper halves of their respective bones 



