GENERAL PHYSIOLOGY OF MUSCLE AND NERVE. 1 1 5> 



a gradual fall of the curve of incomplete tetanus, due to the effect of fatigue 

 on the contracture; e, complete tetanus, but continued gradual declme in the 

 height of the curve under the influence of fatigue. 





Fig. 50.— Effect of frequent excitations to gradually produce tetanus. Experiment on a gastrocnemius 

 muscle of a frog, similar to the last. The weight was only 10 grams. The rate of excitation was 100 per 

 minute. This muscle had been worked a short time before this series of contractions was taken, and, as 

 a result, the introductory and staircase contractions were absent and contracture began much sooner 

 than in the experiment recorded in Figure 48. The record in section b is a continuation of that in 

 section a. 



The following experiment, Figure 52, differs from those which have preceded 

 it, in that the muscle, instead of being directly excited, was stimulated indirect ly 

 by irritation of its nerve. Each shock applied to the nerve was represented 

 by a separate contraction process in the muscle. The experiment illustrates 

 well the combined effect of the staircase and the contractu re to raise the height 



Fig. 51.— Developmenl anil fatigue of contracture, Experiment <>n a gastrocnemius muscle of a frog. 

 The weight was 10 grams. U In the preceding experiments strong maximal breaking induction shocks 



were used to excite. The rate of excitation was 5 per second, The record appears as a silhouette for the 

 reason that the drum was moving very slowly. 



of the contractions. On account of the more rapid rate of excitation, the 

 contracture came on more quickly than in the preceding experiments ; it did 



