iS PRACTICAL HISTOLOGY. 



the line of demarcation. If the section has been made from bone softened with chromic acid 

 the bone will have a slightly greenish tinge. 



(H). Examine in detail the characters of the cells, and note especially the rows of cells in 

 the deeper part of the cartilage. These rows are produced by transverse cleavage of the cells. 

 One part of a row may lie in the hyaline matrix, while the other half is imbedded in the 

 granular matrix (PI. III. Fig. 6). In some sections an indistinct fibrillation is seen in the lower 

 part of the cartilage between the rows of cells, thus resembling what obtains in calcifying 

 costal cartilage. 



(U] Picrocarmine. Put a section on a slide, and stain it with picrocarmine for twenty 

 minutes to half an hour. Remove all the picrocarmine, and mount it in glycerine jelly (p. 

 xlviii). The glycerine jelly must be melted in a water bath, and when fluid a drop is applied 

 to the preparation by means of a glass rod, and covered at once, before the jelly sets. 



WHITE FIBRO-CARTILAGE. 



PREPARATION. Place a small piece of an intervertebral disc with its adherent bone, from 

 a newly killed sheep or ox in twenty or thirty times its bulk of a mixture of chromic and 

 nitric acid (p. xxxiii). After two to three weeks the bone will be decalcified. Wash the pieces 

 in water to remove all acid, and preserve them in rectified spirit, or ; 



Remove the skin from the tail of a cat ; cut it into pieces an inch long, and place these in 

 chromic and nitric acid fluid. 



Make with a freezing microtome vertical sections of the intervertebral disc ; including 

 the subjacent bone, which will have a greenish colour. Make also transverse sections of a 

 piece of the decalcified tail of a cat or other animal. 



Place a vertical section of an intervertebral disc on a slide. Stain it with strong carmine 

 for ten minutes, or until it assumes a deep red colour. Wash, and mount in Farrant's 

 solution. 



EXAMINATION (L). Observe the relation of the fibrous part of the disc to the subjacent 

 bone. 



(H). The matrix in the ox is distinctly fibrous ; the fibres are very fine, unbranched, and 

 wavy. The corpuscles are nucleated, and enclosed in a distinct capsule. They lie scattered 

 irregularly or in chains between the bundles of fibres. Sometimes the cells are seen to 

 be dividing. Here and there fine dots, the cut ends of the fibres, may be seen (PI. III., 



- 3)- 



Stain with carmine a transverse section of an intervertebral disc from the already 

 softened tail of a cat. Remove the surplus staining fluid with blotting-paper, and mount in 

 Farrant's solution. 



EXAMINATION (L). Observe the concentric arrangement of the parts of the disc and 

 the different directions of the fibres composing each layer of it. 



(H). Observe the fibrous character of the matrix and the corpuscles as before. Here 

 and there are transverse sections of the ends of the fibres, which appear like fine granules. 



