232 PHYSIOLOGY OF MUSCLES AND NERVES. 



composed of regularly arranged particles, each of which 

 consists of a small portion of the simply refracting 

 elementary substance, in which is embedded a group 

 of tlic double-refracting disdiaclasts. Such a particle 

 may lie called a muscle-dement. The muscle-fibre 

 would accordingly consist of regularly arranged muscle- 

 elements, the sequence of which, in the longitudinal 

 direction, forms the fibrilla3 of which mention has been 

 made; in the lateral direction forms the discs into 

 which the muscle-fibre may separate under certain 

 circumstances. A diagram of a piece of muscle-fibre 

 would, therefore, present an appearance somewhat a> 

 in fig. 62, in which each of the small rectangular 

 figures represents a muscle-element. Each such muscle- 

 element is, therefore, in all essential points an entire 

 muscle, for the fibre is but an accumulation of such 

 muscle-elements, each exactly like the other ; and the 

 whole muscle is but a bundle of homogeneous muscle- 

 fibres. Iri each muscle-element we must, therefore, 

 recognise the presence of all the qualities which belong 

 to the whole muscle. It possesses the capacity of 

 becoming shorter, and at the same time thicker; and 

 finally and this is the gist of the question here under 

 discussion it has the same eleetric characters as are 

 observable in the entire muscle. 



4. We therefore assume that every inu>c!e- l.-nn-iit. 

 i- the seat of an electromotive force, in \irtue <>f \\hich 

 it is positive on the longitudinal section, negative \\ 

 the cross-section. If a single muscle-element of this 

 sort were surrounded by a conducting substance, sys- 

 tems of current-curves from t lie side of the lon^it udinal 

 M-ction to that <>f the cross-section would be present 

 within it. If many such muscle-elements are arranged 



