ANIMAL MECHANICS. 



253 



to me that the extension of the forearm precedes the backward 

 motion of the arm by a very short interval.* 



In Fig. 66, I have drawn to scale the relative positions of 

 the various sockets, and origin and insertion of muscles in the 



X 



Fig. 66. 



arm of the Bengal Tiger. In this figure, /Sis the centre of the 

 shoulder joint, 0 is the centre of origin of triceps longus, Mis 

 the centre of origin of teres major, X is the extremity of the 

 bisector of vertical angle of latissimus dorsi, C is the centre 

 of the elbow joint, / is the centre of insertion of the triceps 

 long us. 



The measurements of the fixed lines in the Tiger are as 

 follows : — 



SO = 5.62 inches. SM = 9.50 inches. 



SC = 10.50 ,, SX =16.12 



CI = 3.00 ,, SQ = 2.89 „ 



* In the action of a Horse, walking or trotting, the forearm always moves 

 before the arm, by a perceptible interval. 



