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



placed it external to the sarcolemma ; had described the nuclei as 

 being situated in the membrane, and the whole structure as being an 

 organ more analogous to the nerve bulbs invested by the sac-like 

 sheath of the nerve. The opposite views that Krause took on these 

 points to the descriptions given by Rouget, Waldeyer (35), Letzerich 

 (37), and Engelmann, were based on the application of uncertain 

 methods of investigation, especially in the attempt to establish the 

 presence of a sharply denned line belonging to the sarcolemma between 

 the contractile substance and the substratum of the nerve plate which 

 he obtained by the coagulation of the muscle in bichromate of potash, 

 or by the examination of the transverse sections of dried muscle. The 

 lines thus produced do, indeed, lie subjacent to the sarcolemma. It 

 is conceivable that Krause, and perhaps also Letzerich, if the author 

 rightly comprehends the latter, perceived in the nerve eminence the 

 first indications of the nerve plate ; that which Krause described as a 

 pale terminal fibre ending in a bulb being a portion or an optical 

 longitudinal section of the nerve plate, whilst that which Letzerich 

 compared to fluid wax was the plate itself. Thus, in the first inves- 

 tigation on the muscles of Reptiles in Germany, the nerve plate was 

 recognised (47) as the immediate and proper terminal organ of the 

 axis cylinder, whilst it was at the same time established that the 

 granulated and nucleated mass previously taken for it was only the 

 substratum of the plate. That which Rouget, Engelmann, Waldeyer, 

 and Krause regarded as the nerve plate, advantageously exchanged its 

 name for that of nerve eminence (Doyere's cone), in order to preserve 

 the otherwise very appropriate term of terminal plate for the true ex- 

 tremity of the nerve, which expresses well the peculiar form that it 

 presents. The nerve plate was soon recognised as an essential con- 

 stituent of the nerve eminence in the muscles of warm-blooded 

 animals and of man (48). In the meantime Rouget (43) and Krause 

 (41), in the case of the frog, pursuing the method suggested by Wal- 

 deyer, who also believed he had seen a nerve eminence in that animal, 

 adopted another view, Krause describing in the muscles of the frog 

 extremely minute nerve eminences which he believed to be situated 

 externally to the sarcolemna, and to which long, pale, and delicate 

 nerve fibres ran, whilst Rouget considered that the nerves ended by a 

 blunt extremity at the sarcolemma, which was itself continuous with 

 the sheath of Schwann. Neither a nerve eminence, nor any similar 

 prolongation of the axis cylinder is present, according to Rouget, in 

 the muscles of the frog. The true intra-muscular termination of the 

 nerve again apparently escaped the observation of both observers ; for 



