CARTILAGE 161 



the pressure of the cover glass ; examine with low and 

 high powers : note : 



i. The vascular connective tissue meshwork, in which 

 lie the fat cells. 



ii. The fat cells : large, spherical, or from mutual 

 pressure polyhedral, cells ; distended with fatty 

 matter, and with their nuclei near the surface. 



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 im- 

 bedded 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 carti- 

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

 contradistinction to fibro-cartilage, in which the matrix ia 

 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 examine with low 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. 



L 



