JOURNAL OF MICROSCOPICAL SCIENCE. 



DESCRIPTION OF PLATE II, 



Illustrating Messrs. Lister and Turner's paper on the 

 Structure of Nerve-fibres. 



Fig. 



1. — Represents part of a transverse section of the sciatic nerve of a cat 

 hardened by chromic acid, and tinted with carmine ; the axial cylinder 

 alone having received the colouring matter. The specimen was 

 dried and viewed as an opaque object. 



2. — Shows the appearance of thin transverse sections of some nerve-fibres 

 from the same nerve, simply hardened in chromic acid, and ex- 

 amined moist by reflected light. The axial cylinder has, under this 

 low magnifying power, the aspect of a mere space. 



3. — Similar objects to those of fig. 2, but seen by transmitted light. 



4. — A highly magnified transverse section of a nerve-fibre from the same 

 source, prepared like those of figs. 2 and 3, and then tiuted with 

 carmine. The carmine colour is seen to affect only the axial 

 cylinder; and the investing membrane, which, at one part, is torn up 

 from the fibre. This sketch also shows the faintly granular structure 

 of the axial cylinder, and the irregularly concentric striation of the 

 medullary sheath. 



5.— A transverse section of a columnar portion of .the spinal cord of a cat, 

 also prepared with chromic acid and carmine, and examined moist by 

 transmitted light. The fibres vary much in size, but all of them 

 resemble those of the sciatic nerve in having the red axial cylinder 

 surrounded by a ring of untinted medullary sheath. 



6 — 10 are highly magnified views of some fibres in a section of the cord 

 like that of fig. 5. They present the same characters as the fibres of 

 the sciatic nerve. 

 11. — A. fibre from a longitudinal section of a columnar portion of the cord, 

 prepared in the same way. The axial cylinder alone is carmine 

 coloured, and is, in some parts, stripped of its investing sheath, the 

 fibroid arrangement of which is also displayed. 

 12. — A small fibre under similar circumstances. 

 13.— Fatty matter in a state of arborescent fibroid aggregation. 



