Tlif Electrical Response of Muscle 



215 



four records were taken while the muscle was being cooled again to 9° C. 

 The table on the following page gives the period of the first wave in each 

 record, and of a second when a second complete one was on the plate, in 

 thousandths of a second (cr). It also gives the frequency of the wavelets 

 on the first wave in as many of the photographs as they were distinct 

 enough to be counted. 



oi sec. 



i 



Fig. 1. — KeHex electrical ii's(ioiisi'.s ol' tiog's gastroc ii eiui us (strvcluiiiie). Si)iual cord at 

 1-i' C. in all. The muscle at I'i' C. in A. at 10' C. in B, at 7° C. in C, at 12' C. in D. 

 Recording surface describing an arc. R;ite of movement indicated by 500 fork tracing 

 above. It was considerably slower in C and D than it was in A and B. s is tlie signal 

 key, the break of which prouncfd the cxcitntion. 



The results obtained from each experiment of this kind were so uni- 

 form that only six of them, not all on curarised frogs, were made. In all 

 the wavelet freciuency changed when the temperature of the muscle was 

 changed, while that of the waves remained unaltered, i.e. the wave-length 

 varied no more than it usually does when a succession of responses are 

 recorded all with the muscle (as well as the cord) at the same temperature, 

 and it did not vary in any definite direction with the temperature of the 

 muscle. In only one, as it happens, out of this set of experiments were 



