66 ANIMAL MECHANICS. 



Perpendicular. 



1. Biceps femoris (long head), . . 0.95 in. 



,, (short head), . . 0.56 ,, 



2. Semitendinosus, ...... 0.40 



3. Semimembranosus, 0.65 ,, 



4. Gracilis, 0.25 



5. Sartorius, 0.00 ,, 



The cross sections of the muscles that bend the leg were 

 found to be in the same subject* — 



1. Biceps femoris (longhead), . . 2.59 sq. in. 



,, (short head), . . 1.14 



2. Semitendinosus, 1.87 



3. Semimembranosus, 2.25 



4. Gracilis^ 0.89 



5. Sartorius, 0.59 



9.33 sq. in. 



Hence we find, for the determination of K (the coefficient of 

 muscular contraction per square inch of cross section), 



f o-95 x 2.59 

 I + O.56 x 1. 14 

 + O.40 x 1.87 



37 x 16J =Kx J Z 



Dl 2 ] + O.65 x 2.25 



+ O.25 x 0.89 

 L + 0.00 x 0.59 



or, 



r 2.460 

 I + 0.638 

 + 0.748 

 + 1.462 

 + 0.222 



L + 0.000 



610.5 = K > 



5-53° 



* This was also the subject in which I had measured the muscles of the 

 forearm, described in Example, No. 1. 



