riIYSIOLO(.\ OF MUSCLES AM- NKRVKS. 



quarter of an hour by allowing his imagination to 

 -any the hypotheses further than tin- point up to 

 which they are based on known facts; but he docs not 

 presume to urge the results on others. 



Filially, we have to examine how far t he hypothesis 

 to which we have given the preference is confirmed by 

 the phenomena observable in entire muscles. The 

 tendonous covering on the ends of muscle-til ires may 

 be regarded as a layer of non-active conducting sub- 



-tance. In so far as the same phenomena are ex- 







hibited in the uninjured muscle, as in the muscle- 

 prism or muscle-rhombus with its artificial cross 

 section, nothing need be added to the previous ex- 

 planations. But this is, as we have s -en, though 

 nerally. yet not always the case. The natural CTO8E 

 section of a muscle is generally very slightly negatixe. 

 sometimes not at all, as compared with the longi- 

 tudinal section; but the negative character becomes 

 marked as soon as the natural cross-section has been 

 destroyed in any way, either mechanically, chemically, 

 or thermieally. In explanation of this condition of 

 the natural ends of muscle-fibres, we may assume that 

 the arrangement of the molecules in the latter or in 

 the, terminal mu>c|e-element s in each mii-cle-fibiv may 

 sometimes be dit'f'eren! from that at all other points. 

 If, for example, the cro-- sect ion in the terminal 

 muscle-element were not negative, the miiM-le-libre 

 could afford no current, though such a current would 

 arise as soon as this terminal muscle-'lemeii! wa- re- 

 mo\ed or was traii-forim d into a non-active conductor. 

 I 1 ], du I'>oi--h'eymond has lately succeeded in discover- 

 ing a verv probable iva-on for this abnormal condition 



of the ends of muscle-fibres j but without entering too 



