ANIMAL MECHANICS. 



261 



formity with Proposition B ; and it is easy to see from the 

 figure, that the angles £0/and GBY will pass through right 

 angles at nearly the same time. The gastrocneme muscles, in 

 the hind leg, therefore, stand in the same relation (mechani- 

 cally} to the hamstring muscles, that the triceps longus and 

 its allies bear to the latissimus dorsi and teres major, in the 

 fore leg. 



I have found the following weights of the hamstring and 

 gastrocneme muscles in the Felidse :— 



Hamstring Muscles in the Felidce. 





Tiger. 



Lion. 



Jaguar 

 (female). 



Leopard. 



Biceps femoris, . . 



47.60 oz. 



27.75 OZ. 



3-77 oz. 



9.66 OZ. 



Bicipili accessorius . 



1.28 „ 





0.14 



0.18 „ 



Semitendinosus, . . 



13-70 „ 



10.00 )3 



1.58 „ 



3.28 „ 



Semimembranosus, . 



2 3-40 „ 



26.25 » 



261 „ 



S-36 „ 



Gracilis, .... 



13-35 » 



9.00 ,, 



O.92 



241 „ 



Total 



99.33 oz. 



73.00 OZ. 



9.02 oz. 



20.89 oz. 



Gastrocneme Muscles in the Felidos. 





Tiger. 



Lion. 



Jaguar (female). 



Leopard. 



Gastrocnemius externus, 



9.80 oz. 





' * ( 



4.93 OZ. 









| 2.84 oz. j 



Gastrocnemius internus, 



9-50 „ 







2.38 



Plantaris, 



7-35 v 









Total 



26.65 oz. 





2.84 oz. 



7.31 oz. 



It will be observed, that, while the hamstring muscles are 

 attaining their position of maximum effect upon the hip joint, 



