Chap. VI.] 



CARTILAGE. 



47 



dition of a layer or layers of hyaline ground substance ; 

 this is the most recently-formed part of the matrix, but 

 is still distinct 

 from the rest of 

 the ground sub- 

 stance. 



56. In some 

 places, especi- 

 ally in articular 

 cartilage (Till- 

 manns, Baber), 

 bundles of fine 

 conne ct ive 

 tissue fibrils 

 may be noticed 

 in the hyaline 

 ground sub- 

 stance. 



57. In some 

 cartilages, the 



protoplasm of the cell becomes filled with fat globules 

 (Fig. 30c). This fact may be observed in many normal 

 cartilages ; sometimes the fat globules 

 become confluent into one large drop, 

 and then the cell has the appearance of 

 a fat cell. In age, disease, and defi- 

 cient nutrition, lime salts are deposited 

 in the ground substance, beginning 

 from the circumference of the cells. 

 The earthy matter appears in the shape 

 of opaque granules, or irregular or 

 angular granules. The ground sub- 

 stance thereby loses its transparency, 

 becomes opaque in transmitted, white 

 in reflected, light, and, of course, very 

 hard and brittle. This process is the calcification of 

 cartilage. It is also met with in cartilage that is to be 



Fig. 30s. From a Preparation of the Sternal 

 Cartilage of a Newt. 



The lacunae, containing the cartilage cells, anastomose 

 by fine channels. 



Fig. 30c. Three Car- 

 tilage Cells filled 

 with Fat Droplet?. 

 From the hyaline 

 cartilage of the 

 nasal septum of 

 Guinea-pig. 



