2IO 



PRACTICAL HISTOLOGY. 



[xvn 



with i per cent, osmic acid, wash away the osmic acid, add picro- 

 carmine, and place the whole for 24-48 hours in a ruoist chamber 



a, 



FIG. 193. Neuro- 



192. Part of the Human Sympathetic Nerve in keratin Network 



Osmic Acid. There are two medullated fihres in a Medulluted 



amongst Remak's flhres, x 350. Externally the Nerve-Fibre, 



epineurium, Epn; mF. Medullated fibres with 

 Ranvier's nodes; K. Nuclei of Remak's fibres; 

 inlF. Remnk's fibres ; K'. Nucleus of medullated 

 fibre ; Bz. Connective-tissue cells. 



(fig. 47), and afterwards displace the picro-carmine by glycerine, 

 as recommended at p. 82. 



(H) Observe a few small medullated fibres (blackened by Os(> 4 ), 

 and numerous non-medullated fibres, some of which may bo seen to 

 branch. Note the oval nuclei on the fibres (fig. 191). If the part 

 be taken from near a ganglion, often nerve-cells may be seen. 



ADDITIONAL EXERCISES. 



8. Neurokeratin Network and Axis-Cylinder. Place the fresh sciatic 

 nerve of a frog in a dilute solution of ferric chloride consisting of 



Liquor ferri perchloridi . . . . I part 

 Distilled water or spirit .... 3-4 parts. 



