1229 



fi'oni the microscopical extiininatioii of the intercostal muscles of the 

 seventh intercostal sjtace. Pieces of these muscles were cut out, 

 stained after the method of Biki.schowsky and afterwards cut into 

 serial sections of lOji — 30,a and studied. 



The staining reaction gave excellent results, even the finest neu- 

 rofibrillar threads being distinctly visible in the sections, and from 

 the examination of the serial sections the following conclusions nia}' 

 be drawn : the axis-cylinders and the myelinic sheaths of the motor 

 and sensory nerve- fibres weie entirely degenerated and had disap- 

 peared. Only the neurilemma and the nuclei of Schwann remained 

 visible in the form of the curious protoplasmic bands of BtJNGNER, 

 so characteristic for degenerated nerve-fibres ; of the original motor 

 end-plates no trace was to be found, only the thickened layers of 

 multinucleated granular sarcoplasm (soles) were to be seen, indica- 

 ting the place of the original motor end-plates, the neurofibrillar 

 structure itself having entirely disappeared. So the motor and sensory 

 nervous elements of the intercostal muscle-fibres of the 7^'' intercostal 

 space were absolutely degenerated. Not a single medullated nerve-fibre 

 was left intact. But then there appeared in the sections between the 

 muscle-fibres thin bundles of fine non-medullated nerve-fibres, often 

 composed only of two or three threads (fig. 1 and 2), and when wo 

 follow these fibres under the microscope until the point where they 

 seem to end, they appear to be connected with the muscle-fibres by 

 means of very small and delicate end-organs, end-rings or loops or 

 small endnets (fig. 1, 2). Not only at the end of the nerve-fibres, 

 but also here and there in their course, often small side-branches 

 are given off, which come into connection with the muscular fibre 

 across which the nerve-fibre is running, by means of the same small 

 endrings. A look at fig. 2 gives a better idea of the structure and 

 form of these different endrings than a long and detailed description. 

 Fig. 1 teaches us, that besides the small endrings and endnets more 

 complexly built structures occur also, but even these are always 

 finer and more delicately built than are the common motor end-organs. 

 This case besides shows us the terminal ramifications of the neuro- 

 fibrillar structure lying embedded in a layer of granular sarcoplasm 

 which contains a number of nuclei (3). This seems to indicate, that 

 the endorgan in question has a hypolemmal position. 



In fine, the form of these end-organs and their neurofibrillar 

 structure are exactly identical with that of the terminal ramifi- 

 cations and end-organs of the non-medullated nerve-fibres, which 

 remained intact in the eye-muscles after the stem of the eye-muscle 

 nerves had been cut through (Boeke, J 91 J, 1916), and we may 



