NATURAL ATTITUDE AND GAIT OF MONKEYS. 139 



taken from tlie life, slievv how unnatural and inconvenient 

 the erect posture is to them ; they are drawn with the front 

 hands leaning on a stick, while the posterior ones have the 

 toes bent something like a clenched fist *. 



The circumstances in the structure of the monkey kind, 

 which render them unsuited for the erect attitude, have been 

 already in part explained, viz. the narrowness of the pelvis, 

 the short and weak lower limbs, the angle formed by the 

 thigh at its junction with the trunk, and thai between the 

 leg and thigh, the small size of the muscles composing the 

 buttocks and calves, and the slight prominence of the os 

 calcis, which bone does not come to the ground. It may 

 be added, that the exterior margin of the foot chiefly rests 

 on the ground in the simile ; which circumstance, while it 

 leaves them a freer use of their thumb and long toes in 

 seizing the branches of trees, renders the organ so much less 

 adapted to support the body on level ground. The plantaris 

 muscle, which is very fleshy in the monkey kind, instead of 

 terminating, as it does in man, by insertion in the os calcis, 

 passes over that bone into the sole, and is there connected 

 with the plantar aponeurosis and flexor perforatus, so that 

 it may be regarded as making a part of both f. In other 

 quadrupeds it holds the place of the flexor perforatus, enter- 

 ing the foot over the os calcis. These arrangements are 

 quite incompatible with the erect attitude, as the tendon 

 would be compressed, and its action impeded, if the heel 

 rested on the ground. The thumbs, both of the fore and 

 hind hands, have no separate flexor longus in the monkeys, 

 but receive tendons from the flexors of the other fingers J, 

 Hence the thumbs in these animals will generally be bent 

 together with the other fingers ; and they are less capable of 

 those actions, in which the motion of the thumb is combined 



* SeeVosMAER's figure as copied by Blumenbach, Ahbild. n.h. Gegenstcinde, 

 No. 1 2, Tyson, fig. 1 & 2. The sitting attitude of Mr. Abel's figure, in which 

 the extremities are all gathered up to the trunk, is much more natural than 

 the erect position in which the monkey tribe are often represented. 

 + VicQ u'AzYR, Discours sur TAnatomie, (Euvres, t. iv. p. 149. 

 X See the work above quoted. 



