i86 Striated Muscle Contraction [Jan. 



cm., and if this were maintained thruout the entire contraction 

 phase, and if striated muscle were a mechanism having an efficiency 

 of loo per Cent., then the surface energy in i cc. of muscle would 

 enable it to lift a little over looo grams^^ and surface energy might 

 be regarded as the cause of muscle contraction. 



The efficiency of the muscles of the human body as a machine is 

 very close to 21 per cent.,^^ and it is almost certain that if any of 

 the driving force in striated muscle is due to surface tension at all, 

 the tension is but a small fraction of 85 dynes. The above figures 

 should be interpreted accordingly. 



Washington, D. C. 



23 Berg : Biochemical Bulletin, 1912, ii, p. 109. The value, 361 grams, is to 

 be multiplied by 3.1416, the value of tt having been accidentally omitted. The 

 correct figure is, therefore, 1134 grams. 



24 Benedict and Carpenter : Bulletin 208, Office of Experiment Stations, U. S. 

 Dept. of Agric, 1909, pp. 1-44. Hill : Joiir. of PhysioL, 1913, xlvi, pp. 435-469. 



