LESSON XV. 



PERIPHERAL GANGLIA AND NERVE CELLS. 



1. Transverse section of spinal ganglion 1 . (Osmic 

 acid ; paraffin.) Mount in balsam (cp. Less. vi. 4). 



a. Note with a low power; the sheath of the 

 ganglion; the numerous nerve cells with medullated 

 nerve fibres between them, comparatively few nerve 

 fibres being present between the more peripheral cells ; 

 the transversely cut nerve fibres chiefly grouped at one 

 side of the section. (The fibres of the anterior root 

 may form a separate bundle with a distinct sheath.) 



6. Note with a high power 



The nerve cells of various sizes, the small ones as 

 a rule being stained more deeply than the large ones ; 

 the cell substance varying from nearly homogeneous to 

 coarsely granular ; the large spherical nucleus, and large 

 nucleolus or nucleoli. 



The numerous large nerve fibres ; some fibres will 

 be seen coiling amongst the cells in the plane of the 

 section. 



1 In 1 to 3, the ganglion of a cat or dog may be taken. Speci- 

 mens 1 and 4 should be mounted on the same slide. 



