ANIMAL MECHANICS. 



403 



Comparison of Man and Quadrumans — Glutceus primus and 

 Tensor vaginae femoris. 





Percentage T> elativ „ 



Successive 

 Differ- 

 ences. 



1. Man, .... 



2. Gorilla, . . . 



3. Chimpanzee, . . 



4. Hamadryas, . . 



5. Rhesus, . . . 



6. Cynomolgus, . . 



7. Ateles, .... 



8. Mandrill, . . . 



20.61 I CO 

 i5- 39. 74 6 

 1 1 . 67 566 



9 33 1 45-3 

 6.78 : 33.0 

 5.38 ! 26.1 

 4. 96 24 1 

 3.72 18. 1 



25-4 

 43-4 

 n-3 

 12.3 

 6.9 

 2.0 

 6.0 



This Table shows that the difference between Man and the 

 Gorilla is greater than the differences between the Quadru- 

 mans compared with each other. 



The remarkable differences between Man and the Quad- 

 rumans, found in the muscles of the Hip joint, are further 

 illustrated by an examination of the muscles of the foot. 

 These muscles may be divided into three distinct groups, 

 viz. : — 



i°. Walking muscles. 

 2°. Grasping muscles. 

 3 0 . Extending muscles. 



So far as the presence or absence of individual muscles is 

 concerned, the peculiarities of Man's foot consist in — 



i°. The presence of the peronoeus tertkis. 



2°. The absence of peronceus quinti. 



3 0 . The absence of extensor internodii hallucls. 



The following Tables enable us to compare the relative 

 developement of the various muscles, or groups of muscles: — 

 2 D 2 



