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



the assumption that every muscular fibre must be supplied with 

 at least one nerve fibre, even if this be the result of division, it 

 is obvious that the muscular apparatus of Fishes, divided as it 

 is to so great an extent by tendinous intersections, and which 

 as a consequence of the shortness of these fibres, contains in an 

 equal volume many more individual muscular fibres to be sup- 

 plied with nerves, than the long-fibred muscles of other classes, 

 can receive only a smaller number of primitive nerve fibres. 

 The Fish would indeed have to carry a weighty mass of nerves, 

 were the relation between the two tissues the same as in Mam- 

 mals. Hence, nowhere are so many divisions of the primitive 

 nerve fibres to be so easily found as in the muscles of this class. 



The large relative number of nerves distributed to the ocular 

 muscles, and generally present in all the muscles of Mammals, 

 but as it would appear especially in the muscles of Man, is very 

 suggestive in regard to the exact regulation of their movements, 

 for the uncommonly fine adjustment of the ocular muscles would 

 be unattainable if the excitation of one nerve fibre had as a con- 

 sequence the excitation of as great a number of muscle fibres as 

 in the Frog, and still more as in the Fish. In regard to the 

 general distribution of nerves, allusion may here be made to 

 the 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 desti- 

 tute of nerves for a considerable space. The muscles that are 

 best adapted for the study of the mode of division of the nerves 

 supplying them, are the musculus cutaneus pectoris of the 

 Frog, and also the sartorius, the ocular and digital muscles, and 

 the hyoglossus of the same animal ; the ocular muscles of the 

 Fish, and amongst mammals those of the Cat, and, above all, the 

 thin muscles which extend from the vertebral column to the skin 

 in the Snake. These may be examined almost whilst yet still 

 living, and merely flattened by a covering glass, or after being 

 rendered transparent by means of a 1 per cent, solution of 

 hydrochloric acid. 



After the discovery of Doyere had shown the mode of con- 

 nection of nerves without sheaths, with similarly naked muscular 

 bands, the question naturally arose from a purely morphological 

 point of view, whether transversely striated muscle, which 



