IX] HYALINE CARTILAGE 67 



another in acid hsematoxylin (diluted as usual) for 

 5 to 10 minutes. Mount the former in glycerine, and 

 the latter in balsam. 



Observe that the cells are arranged in groups (each 

 group having arisen by division from a single cartilage 

 cell), note the outline of the thin layer of newer carti- 

 lage (capsule) around each cell ; sometimes the whole of 

 the cells in a group may be seen to be also surrounded 

 by a thin layer just marked off from the rest of the 

 matrix. Towards the outside of the cartilage the cells 

 become flattened in a direction parallel with the 

 surface. 



4. Take a piece of costal cartilage from a recently 

 killed oldish animal ; cut thin transverse sections either 

 free-hand or with a freezing microtome and transfer 

 them with a brush to a watch-glass containing normal 

 salt solution. Mount one section in normal salt solution. 

 Place another in two or three drops of osmic acid '5 p.c. 

 in a watch-glass and cover it up. 



a. In the former observe under a high power, that 

 The cells frequently show signs of partial degenera- 

 tion, containing fat globules which may be nearly as 

 large as the cell ; these are very highly refractive and 

 so have a very distinct outline. 



In places the matrix may be fibrillated and towards 

 the centre of the section there may be a nodular semi- 

 opaque deposit of lime salts. Irrigate with 1 p.c. 

 hydrochloric acid; the calcareous deposit is dissolved, 

 but the fibrillation is not affected (it differs thus from 

 the fibrillation of white fibrous connective tissue, cp. 

 Lesson x. 2). 



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