Huber-DeWitt, Nerve- Endings in Muscles. i8i 



laries, embedded in the gelatinous connective tissue." This 

 opinion is very largely confirmed in his second paper. 



In the account given by Retzius, who has worked on the 

 motor nerve endings in frog's muscle with methylene blue the 

 following statement may be found: "An den Methyleneblau- 

 praparaten konnte ich ferner nie sicher sehen, ob die Endplat- 

 ten auf oder unter dem Sarcolemma liegen, so dass ich zur 

 Losung dieser alten Streitfrage nichts beitragen kann." And 

 again, — "Die leichte, reine Farbung der Nervenfasern und 

 ihrer Endscheiben, ohne gleichzeitige Farbung des Inhalts der 

 Muskelfaser, scheint mir inc^essen fiir eine Anhaftung an der 

 Aussenseite des Sarcolemmas zu sprechen, denn an den abge- 

 rissenen Enden der fraglichen Muskelfasern sah ich in der Regel 

 gleichzeitig eine diffuse Blauung des Muskelfaserinhalts. " 



This question, it seemed to us, might be most satisfactorily 

 answered in cross and longitudinal sections of the motor end- 

 ings in amphibian muscle stained in methylene blue and further 

 treated as designated. Two such cross sections are shown in 

 Figs. 13 and 14. It may here be seen that the ramifications of 

 the axis cylinder are under the sarcolemma terminating in a 

 relatively thin layer of sarcoplasma, which layer of sarcoplasma 

 is continuous with that found between the muscle fibrillae. 



The conditions here presented being therefore very similar 

 to those found in such vertebrates as present a localized motor- 

 ial ending, with the distinction that in the latter the axis cylin- 

 der terminates in a localized elevation — the sole — which has been 

 interpreted as being a circumscribed accumulation of sarco- 

 plasma, while in amphibia the sarcoplasma surrounding the 

 ramified ending of the axis cylinder, extends, like it, over a 

 larger proportionate area of the muscle fibre. 



The figures here shown, and many others that might be 

 sketched, would seem to confirm most fully the belief in a 

 hypolemmal ending of the axis cylinder in striped muscle of 

 amphibia. In fresh methylene blue preparations of the motor 

 endings, studied in a thin muscle, as for instance the cutaneus 

 pectoris (Ecker), the axis cylinders of the meduUated nerves 

 may be traced with the utmost clearness into the ramifications, 



