138 KUHNE'S NERVELESS ZONES IN MUSCLES. 



(p. 589) ; but that in those two nerveless zones, though the ex- 

 citability was at a minimum, still with a certain strength of 

 electric current contraction could be excited, and if the motor 

 nerves were paralyzed by an upward current, that low degrees 

 of excitability extended through the whole muscle. This last 

 circumstance is difficult to explain on Beale's theory, but 

 Kiihne says it is very difficult to get it to succeed, so perhaps 

 we may wait till it is confirmed. In the meantime we may 

 notice that in Strieker's Handbook, in 1870, Kiihne still main- 

 tains the assertion of the absence of nerves in portions, and 

 makes it even more general, describing it as a well-known fact 

 *' that considerable segments of every muscle may be met with 

 in which no nerves are to be found, and that in particular the 

 extremities of the muscles appear to be destitute of nerves for 

 .a considerable space" (p. 204). This, in spite of Beale's well- 

 known observations according to which the most important 

 part of the nerve, as conductor of force, begins where Kiihne's 

 nerve seems to end. 



" The active part of the nerve-fibre, as regards the elementary 

 muscular fibre, commences only at the point where the dark- 

 bordered character of the nerve fibre ceases, and it therefore 

 follows that the most important, and most active portion of the 

 peripheral nerve fibres distributed to muscle, has escaped the 

 observation of many observers. The fibres are extremely deli- 

 cate, and, like other very fine nerve fibres, can only be rendered 

 visible by special methods of preparation. Every nerve fibre, 

 however fine, is compound, being composed of several fine 

 iibres. ' Nuclei' are invariably found in relation with these 

 fibres, and they vary in number in different cases " (" Biopl.," 

 p. 273). 



Perhaps we can account for this discrepancy when we know 

 that the finest nerve fibres are invisible in the living body, and 

 Kiihne's preparations are directed to be made by macerating 

 with dilute sulphuric acid, dissolving the connective tissue by 

 warming to 104 F., isolating the muscular fibres by vigorous 

 agitation with water in a test-tube, and then pencilling away 

 the still adhering capillaries with a camel-hair brush. It would 

 be difficult to imagine a better way of removing the plexus of 



