54 , ANATOMY OF VERTEBRATES. 



Quadrumana, than in Man, thus enabling the muscles to continue 

 their action as finger-benders when the hand itself is flexed. 

 The fasciculus of the e flexor profundus ' which sends the tendon 

 to the last phalanx of the thumb, is more distinctly a ' flexor 

 longus pollicis ' in Apes than in lower Quadrumana. In the 

 Aye-aye it adheres to the supplementary carpal and fascia on its 

 way to the thumb, and thus opposes both the last phalanx and the 

 \ pad ' at the base of the thumb in the act of grasping. The 

 ' flexor brevis,' the ' abductor,' the c adductor,' and { opponeus 

 pollicis ' are present in the Chimpanzee and Gorilla, as are like- 

 wise the ( extensor longus ' and ' extensor brevis.' In the Orang 

 these muscles begin to be confounded ; in most lower Quadru- 

 mana they are blended together. The homologue of the ( extensor 

 indicis' of Man bifurcates and sends a tendon to both the index and 

 medius digits ; the homologue of the extensor minimi digiti likewise 

 splits and sends a tendon also to the annularis ; so that, while in 

 Man the index and minimus only have two extensor tendons, all 

 four fingers (ii — v) have them in most Quadrumana. The hand is 

 thereby the stronger as a suspensor of the body from a bough. 



The ( ectogluteus ' is feebly developed compared with that in 

 Man : the Gorilla, though receding far in this respect, recedes the 

 least. The homologue of the ' gracilis ' is relatively larger in 

 all Quadrumana than in Man, and its insertion is extended 

 lower down the leg. In Stenops the vastus externus contributes 

 a fasciculus to the rectus femoris ; in Chiromys it is as distinct as 

 in higher Quadrumana. But here the mesogluteus exceeds the 

 ectogluteus in size, although the latter is supplemented in the 

 Gorilla by fleshy fasciculi from the ischial tuberosity, which spread 

 their insertions from that of the ectogluteus down the femur to 

 the internal condyle, apparently representing the adductor magnus. 

 In both Orang and Chimpanzee a muscle from the outer border 

 of the ilium to near the acetabulum is inserted into the under and 

 outer part of the great trochanter and rotates the thigh inwards. 1 

 The gastrocnemii have a greater length and minor breadth and 

 thickness of the fleshy part : the soleus rises from the fibula exclu- 

 sively, and joins the gastrocnemii low down. 



§ 201. Muscles of Bimana. — The myologies of Anthropotomy 

 reduce the need of noticing human muscles here to some com- 

 parison with those of highest Apes, bringing out the ordinal 

 characteristics of the limbs, and to the illustration of those giving 

 expression to the face and reflecting the action of the organ that 

 marks Man's place in Creation as the type of a distinct sub-class. 



1 f Scansorius,' Trail, xxxv. « Invcrtor femoris,' xxxiv. p. 68. 



