ANIMAL MECHANICS. 



173 



Hence, 



W = £.688 W = 9.726 sq. in. I Equivalent prismatic biceps 

 L = 1.15 in. ) of Ass. 



The weight of the brachiceus is 3.23 oz., and its length is 

 9 inches ; hence its cross section is — 



w = — ^ — = 0.592 sq. in. I 



9 x 0.000 V Brachiceus of Ass. 



/ - 9 in. J 



In a fine Sambur Stag examined by me, the biceps humeri 

 muscle was found to be pennate in the arrangement of its 

 fibres ; their length being 2.56 in., the angle made by 

 them with the fascia of insertion being 34 0 . The weight of 

 the muscle was 5.91 oz. In this case, the length of the 

 biceps muscle was 10 inches, from which we find its mean 

 cross section 



5-9 1 

 10x0.606 



From this we find, as before, the prismatic muscle equivalent 

 to the pennate biceps — 



L = / sec = 3.09 m. 



^ A cos eh 



W = w — j — 1 = 3.16 sq. in. 



The brachiceus muscle in the Sambur is 4.95 oz. in weight 

 and 9.5 inches in length, and it is a prismatic muscle; its 

 cross section is, 



w = 4-9$ _ 0> 86o sq. in. 



9.5 x 0.606 



It is interesting to contrast together the two muscles which 

 flex the forearm in the three animals described, in order to 

 see, at a glance, the very different uses which these muscles 

 are intended for. 



