iv ELECTROMOTIVE ACTION IN MUSCLE 431 



single short stimulus. Compressed muscle, according to Kiihne 

 (supra), exhibits a similar reaction. 



The complete uniformity of response between desiccated and 

 compressed muscle leads to the conjecture, that the striking 

 tendency to secondary excitation in both cases must be ascribed 

 to one and the same cause, i.e. dehydration, produced in the oneln= 

 stance by slow evaporation, in the other by strong pressure. It is 

 of little consequence that the alteration which produces second- 

 ary excitation concerns the entire muscle in the one case, and 

 only a larger or smaller section of it in the other. Kiihne him- 

 self remarks opportunely that "the muscle comes out of the 

 press as if it had been desiccated," and calls attention in another 

 place to the " dry, dull appearance " of the pressed and flattened 

 strip of muscle, which gives the same constant response even after 

 removal of pressure, so that alteration of the muscle-substance 

 must be held the true cause of secondary activity. In regard to 

 excitability also, there is a general conformity between com- 

 pressed and desiccated muscle, since in both cases it appears per- 

 ceptibly heightened. This is indeed to a much greater degree 

 the case with the slow loss of water by evaporation than in 

 pressure, in which Kiihne only succeeded in demonstrating an 

 unmistakable rise of excitability in the compressed tract at the 

 beginning, while later on, in spite of marked secondary action, it 

 showed a significant decrease of response. For the rest the 

 increase of excitability cannot in itself be regarded as the sole 

 cause of secondary excitation, since it is easy to show that a much 

 more significant rise of excitability produced in another way 

 (effect of Na 2 C0 3 solutions) does not enable the muscles to react 

 on one another as described. Just as little can it be due to the 

 altered time -relations of the excitation, since poisoning with 

 veratrin, which, of course, throws the muscle into a state in 

 which it falls into sustained contracture at the slightest 

 stimulus, would then induce secondary excitation from muscle 

 to muscle, which never is the case. An important point appears 

 on the contrary from the fact that the antagonistic contact 

 of the preparations is incomparably more intimate, when the 

 contiguous surfaces are at a certain degree of desiccation. This 

 may also have some application in individual muscles, where the 

 single primitive fibres lie in closer juxtaposition, in proportion 

 as the muscle loses water. Still it is striking that, notwith- 



