40 THE PHYSIOLOGY OF MUSCLE AND NERVE. 



A series of experiments of this kind furnishes data for con- 

 structing a curve of work by plotting off along the abscissa at equal 



Fig. 17. To show the decrease in extent of contraction of the gastrocnemius muscle 

 of a frog with increase in load. In the first contraction, to the right, the load was 14.2 

 gms. At each successive contractipn the load was increased by 5.3 gms. With a load of 

 182 gms. the lever gave only the slightest indication of a shortening, and this may have 

 been due to some lateral movement. 



Fig. 18. The curve of work obtained by plotting the results shown in Fig. 17. The 

 initial contraction was made with a load of 14.2 gms., and the work done in gram -milli- 

 meters is represented by the ordinate erected at this point. The maximum work was done 

 with a load of 88.6 gms., and the absolute power of this particular muscle was found to be 

 equal to 182 gms. 



intervals the equal increments in load and erecting over each load 

 an ordinate showing the proportional amount of work done. The 



