CARTILAGE. 47 



b. Osmic Acid specimen. 



Note the reduction of the osmic acid by the fat, which 

 becomes stained a dark brown or black colour. 



E. Cartilage. 



In cartilage or gristle the intercellular substance, which in 

 most other tissues is only present in small quantity, is greatly 

 increased so as to far exceed in bulk the cells which it connects 

 together. The intercellular substance forms a dense translucent 

 matrix resembling an extremely stiff jelly, in which are 

 imbedded the cartilage cells, either singly or in groups. In 

 young cartilage the intercellular substance is much less 

 abundant, and the cells consequently closer together than in 

 older or more mature specimens. 



Cartilage when free from other tissue is called hyaline 

 cartilage from the clear or glassy appearance of the matrix, in 

 contra-distinction to fibro-cartilage, in which the matrix is fibrous 

 from admixture with white fibrous or elastic tissues. 



I. Hyaline cartilage. 



a. Cartilage of newt. Take a small piece of cartilage from 

 the shoulder girdle of a newt : scrape away gently any 

 muscle or other tissue that may adhere to it ; mount in 

 normal salt solution, and exami7ie with loiv and high 

 powers. 



i. The intercellular matrix is either hyaline or faintly 

 granular. 



ii. The cartilage cells are imbedded in the matrix; 

 each cell is nucleated, and occupies a cavity or 

 lacuna in the matrix. In places the cells are in 

 groups of twos or fours owing to recent division. 



Wash the specimen thoroughly in water : stain with carmine, 

 and mount as a permanent preparation in glycerine ; examine 

 zvith the high p)ower, and note that 



iii. The cell nuclei are stained deeply, and the matrix 

 very slightly : the layer of matrix immediately 

 surrounding each cell — the capsule — stains more 

 deeply than the other parts. 



