102 PHYSIOLOGY OF MUSCLES AND NERVES. 



the nerves. We must now, therefore, examine the 

 characters of nerves, after which we shall try to explain 

 the nature of their influence on muscles. 



It must also be observed that the distinction between 

 striated and smooth muscle-fibres is not absolute ; for 

 there are transitionary forms, such as the muscles of 

 molluscs. The latter consist of fibres, exhibiting to 

 some extent a striated character, and, in addition to 

 this, the character of double refraction. At these points 

 the disdiaclasts are probably arranged regularly and in 

 large groups, while at other points (as in true smooth 

 muscle-fibres) they are irregularly scattered and are 

 therefore not noticeable. 



