

HISTOLOGICAL DEMONSTRATIONS. 97 



of these made as follows : Place the cervical sympathetic of a 

 rabbit in J per cent chromic acid for two or three days. Tease 

 a small piece with needles, stain with logwood, and mount in 

 glycerine. A spindle-shaped nucleus brightly stained can be 

 seen here and there in the course of a fibre. The nuclei ap- 

 pear to belong to the gray sheath enclosing the nerve fibrils. 



154. Examine (H.) a preparation of cornea, showing 

 primitive nerve fibrils stained with gold, as directed in 

 232, b. A network of fibrils is seen. The fibrils have 

 usually a beaded appearance. A power of 800 or 1000 

 diam. is advantageous for their examination. 



CENTRAL NERVE TERMINATIONS. 



155. Nerve Cells (H.) Make a section with scissors 

 of the Gasserian ganglion of a sheep or other animal 

 recently killed. Tease the section gently in a drop of salt 

 solution ; cover, and examine. The nucleus, nucleolus, and 

 general protoplasm of the nerve cells can be readily seen. 

 The processes of the cells are usually broken off. 



If such a preparation be teased in a drop of magenta instead of salt 

 solution, the cells are readily stained, and the axial cylinders of the white 

 nerve fibres may often be found torn out of the medullary sheath and 

 stained. 



The membranous capsule, with its nuclei around each cell, may be 

 demonstrated by freezing a fresh Gasserian ganglion, and staining the 

 sections with magenta. 



156. Examine (H.) multipolar nerve cells from the 

 hardened spinal cord prepared thus : Cut the fresh spinal 

 cord of a calf into pieces about a quarter of an inch in 

 length. Place them for a month in one per cent potass, 

 bichrom. solution. Remove a thin slice of the gray matter 

 of the anterior horn with scissors, tease with needles, stain 

 with carmine, and mount in glycerine. Or freeze the fresh 

 cord of the calf; make transverse sections. Place them in 

 \ per cent osmic acid for twenty-four hours ; wash in water, 

 and examine in potassium acetate. Or place them for a 

 day in iodised serum, and then examine. 



Each cell has a nucleus and a nucleolus and several 

 processes. With a power of about 1000 diam. the 



H 



