CHAPTER V. 



THE MODE OF TERMINATION OF NERVE FIBRE IN MUSCLE. 

 BY W. KUHNE. 



WE exercise control over our muscles through the agency of 

 the nerves, and it is through the nerve paths alone that the 

 will excites them to contract. ^ The question therefore naturally 

 arises, In what way do nerves terminate in muscle ? Inquiries 

 were made on this point long before instruments and modes of 

 investigation could furnish any answer, and these led to ever 

 new and ever unsatisfactory researches. 



We now believe that we are able to perceive the direct con- 

 tinuity of the contractile with the nervous substance. Yet it 

 may still happen that, in consequence of further improve- 

 ments in our means of observation, that which we regard as 

 certain may be shown to be illusory. Nevertheless, work is 

 indispensable, and we must press on till we reach the point in 

 the domain of morphology, in which order and law become the 

 last expression of our knowledge. Up to the year 1840 all 

 attempts to give a satisfactory account of the ultimate termi- 

 nation of the motor nerves failed. The admission of loop-like 

 extremities in the muscle can only be regarded as an expression 

 of ignorance, and of the impossibility of following the course 

 of the nerves in muscle with clearness. 



But suddenly and accidentally an unprejudiced observer, in 

 investigating the interesting small Tardigrada, recognised nearly 

 all that we know at the present time regarding the ends of the 

 motor nerves. In 1840, Doyere discovered that the nerve ap- 

 plied itself to the muscular fibre by means of a conical enlarge- 

 ment. Both of these structures are destitute of sheaths or 



