CHAP. IX. MUSOULAR AND KEEVOUS TISSUES. 103 



fibre present this peculiar polarized condition, we 

 may, without any hesitation, infer, that the two 

 forces, the muscular and nerve force, are both polar, 

 and, consequently, that muscular action and nerve 

 action are polar actions. With regard,' however, to 

 the nerve, the mere circumstance of its electrical 

 state will not alone prove that nerve force is polar, 

 as we shall see in a subsequent chapter. 



During life, the muscular and nerve fibre may be 

 considered as existing in a state of tendon', a forced 

 state, and muscular relaxa,tioii may coincide^ and 

 would be synonymous, with this polarized condition 

 or state of tension, and contraction, the result of a 

 depolarization of the muscular fibre. In the normal 

 state, this depolarization is induced by means of 

 nervous agency ; but it may alsb occur from other 

 means, such as chemical or mechanical agencies, 

 or whatever is likely to produce disorganization. 

 Depolarization having occurred, the polarized state is 

 easily and readily restored by the a,atoi. nutrition; 

 hence contraction may be partly considered as the 

 result of molecular attraction^. The particles con- 



' It would be of some importance to ascertain the state or 

 condition of the prisms in the electric organ of the fish, prior to 

 their discharge of electricity. Theoretically, all the tissues in 

 the animal body may be considered as being in an electric or 

 polarized state, .presenting, however, great differences in regard 

 to each other. 



8 I have already alluded to the opinion of Dr. BadclrSe, who 

 considers that muscular contraction is the result of molecular 

 attraction. 



