THE CONNECTIVE TISSUES. 



I II 



dense network which permeates the hyaline matrix (Fig. 79), pass- 

 ing over into the corresponding elements of the perichondrium. 

 Elastic cartilage is found in the external ear, the cartilage of the 

 Eustachian tube, the epiglottis, a portion of the arytenoid cartilages, 

 and the cartilages of Wrisberg and Santorini. 



-Cartilage-cell. 



Elastic fibers. 



Fig. 79- Elastic cartilage from the external ear of man ; X 7^o. a, Fine elastic 

 network, in the immediate neighborhood of a capsule. 



The ground-substance of cartilage undergoes changes as age 

 advances. In certain cartilages there is observed a fibrillar forma- 

 tion, in the ground-substance between the cells. The fibers are 

 coarse and differ from white fibrous or yellow elastic fibers. This 

 change is observed in laryngeal cartilages as early as the twentieth 

 'year, and is sometimes designated as an asbestos-like alteration of 

 cartilage. Calcification occurs in many cartilages laryngeal, 

 tracheal, costal and consists of the deposition in the ground-sub- 

 stance of fine granules of carbonate of lime, first in the immediate 

 vicinity of the cartilage cells. Calcification is observed as early as 

 the twentieth year in the laryngeal cartilages. Ossification may be 

 regarded as a normal occurrence in many cartilages. It begins 

 with an ingrowth of blood-vessels from the perichondrium into the 

 matrix. These vessels are surrounded by connective tissue. Around 

 such locations ossification occurs. Chievitz has shown that the 

 laryngeal cartilages begin to ossify in men at about the twentieth 

 year, and in women at about the thirtieth year; and the tracheal 



