CHAPTER XL 



1. A regular muscle-prism ; 2. Currents and tensions in a muscle- 

 prism j 3. Muscle-rhombus ; 4. Irregular muscle- rhornbi ; 5. Cur- 

 rent of m. gastrocncmius. 



1 . Beginning 1 the study of the electric phenomena 

 exhibited in animal tissues with muscles, we will at first 

 experiment only with single, extracted muscles. Even 

 these, however, exhibit phenomena so complex in some 

 respects, that it will be better to take first a compara- 

 tively simple case. In taking one not exactly under 

 natural conditions if, that is, we use a muscle artifi- 

 cially prepared for the purpose of experiment this pro- 

 ceeding will find ample justification in the greater ease 

 with which we shall thus be enabled to understand the 

 more complex examples which we must afterwards 

 examine. 



Taking a regularly shaped muscle, in which the 

 fibres are parallel, we will cut out a part of this by 

 making two even cuts at right angles to the direction 

 of the fibres. A piece of this sort may be called a 

 regular muscle-prism. It is, according to the shape of 

 the muscle used, either circular or more oval, or flat 

 and band-like ; its shape makes no difference, and the 

 length and diameter are of equally little account. The 

 only essential point is that all the muscle-fibres are 



