CHAPTER VIII. 



CARTILAGE AND CONNECTIVE TISSUE. 



Temporary and Permanent Cartilages. In early life 

 P. great many parts of the supporting framework of the 

 Body, which afterwards become bone, consist of cartilage. 

 Such for example is the case with all the vertebrae, and 

 with the bones of the limbs. In these cartilages subse- 

 quently the process known as ossification takes place, by 

 which a great portion of the original cartilaginous model is 

 removed and replaced by true osseous tissue. Often, how- 

 ever, some of the primitive cartilage is left throughout the 

 whole of life at the ends of the bones in joints where it 

 forms the articular cartilages; and in various other places 

 still larger masses remain, such as the costal cartilages, 

 those in the external ears forming their framework, others 

 finishing the skeleton of the nose which is only incom- 

 pletely bony, and many in internal parts of the Body, as the 

 cartilage of "Adam's apple," which can be felt in the front 

 of the neck, and a number of rings around the windpipe 

 serving to keep it open. These persistent masses are known 

 as the permanent, the others as the temporary cartilages. 

 In old age many so-called permanent cartilages become 

 calcified that is, hardened and made unyielding by deposits 

 of lime salts in them without assuming the histological 

 character of bone, and this calcification of the permanent 

 cartilages is one chief cause of the want of pliability and 

 suppleness of the frame in advanced life. 



Hyaline Cartilage. In its purest form cartilage is flexi- 

 ble and elastic, of a pale bluish-white color when alive and 

 seen in large masses, and cuts readily with a knife. In thin 

 pieces it is quite transparent. Everywhere except in the 



