444 



THE FUNCTIONS OF CROSS-STRIATED MUSCLES 



able to lift the load ; but if the load be diminished, he can continue the work 

 immediately. The fatigue curve either declines rapidly at first and more 



FIG. 179. Ergograph, after Mosso. 



slowly at the end, as in Fig. 180, A, or the fall at the beginning is slight and 

 is rapid toward the end (Fig. 180, B). Judging by Mosso's results every indi- 

 vidual has his own peculiar form of fatigue curve. 



Of the factors which influence the progress of fatigue we shall investigate 

 first the effect of frequency of contraction with a constant load. Figs. 181, A to 



FIG. 180.- 



A B 



-Fatigue tracings obtained with the ergograph of Mosso. To be read from right to left. 



