71 JJ1STOLOGY. 



tendency to arrange themselves in groups (Fig. 38). This 

 cartilage occurs in the nucleus gelatinosus of the inter vertebral 

 ligaments, in the symphysis ossium pubis, in the interarticular 



FIG. 38. 



Nucleus of 

 cartilage cell 



Fibril bundle* 



Fibrous cartilage from the ligamentum teres fetnoris of a dog. X 570. 



cartilages, and in the place of insertion of the ligamentum teres 

 femoris. 



3. Bone. 



Like other supporting tissues, bone possesses a large pro- 

 portion of intercellular substance. The mineral constituents 

 (calcium salts), which are connected closely with the organic 

 parts known as ossein, produce the characteristic hardness of 

 bone. 



By so-called decalcification we are able to dissolve away 

 all the calcium salts and leave only the organic framework 

 which shows the structure of bone completely. On the other 

 hand, we can, by heating the bone (calcination), destroy the 

 organic constituents, and leave a skeleton which consists of salts 

 and likewise presents an exact picture of the bone structure. 

 In this way it is possible to study the finer architecture of 

 bone equally well in decalcified or in dried specimens. 



We distinguish compact and spongy bone substance, the 

 former being dense and firm, the latter resembling the skeleton 



