210 MODE OF TERMINATION OF MOTOR NERVES, BY W. KUHNE. 



inconsiderable space, as compared with the transversely striated 

 contractile material. The muscle fibres are, indeed, dotted 

 with nuclei, which are found not only immediately beneath the 

 sarcolemma, but in all parts of the transverse section ; yet the 

 protoplasmic portion is very small in quantity, and exists only 

 in the form of a few molecules at the poles of the nuclei, or 

 may even be altogether absent. Without methodical investi- 

 gation it is almost impossible to strike upon the precise point 

 in the fibres of the muscles of a frog which displays the mode 

 of attachment of the nerve. This is sufficiently shown by the 

 fruitless results of the observations repeatedly made antece- 

 dently to the last ten years. 



After the experience that had been obtained respecting the 

 connection of the nerves with the transversely striated muscu- 

 lar fibres invested with sarcolemma of the Invertebrata, it was 

 somewhat more than an hypothesis when it was maintained 

 that the conditions must be essentially similar in all animals 

 in which nerves induce the act of contraction, and conse- 

 quently "in the Vertebrata. In order to decide whether every 

 muscular fibre is connected with at least one nerve fibre, it 

 was requisite to isolate the former in its whole length, and to 

 examine its entire superficies. This was effected by the mode 

 of isolating the fibres, suggested by Budge, through the agency 

 of a mixture of chlorate of potash and nitric acid, a plan 

 that was advantageously modified by V. Wittich, who recom- 

 mended that the muscle should be warmed with a very diluted 

 solution of the same mixture. It is still better to soften the 

 intermuscular connective tissue by maceration for twenty-four 

 hours, in an extremely dilute solution of sulphuric acid, and 

 subsequently to convert it into gelatine and effect its solu- 

 tion by warming it for a few hours at 104 Fahr. The isolation 

 of the muscular fibres may then be accomplished by vigorous 

 agitation with water in a test tube. By this method any 

 muscle can be completely broken up into its individual fibres. 

 The capillaries, which still often remain attached, must be re- 

 moved by pencilling with a camel-hair brush. On carefully 

 examining such isolated muscular fibres throughout their whole 

 length, one spot at least may always be found to which a 

 nerve fibre, usually more or less ramified, cleaves. In long 



