Introduction 



29. Adenoid or Retiform Tissue. This is a variety of 

 connective tissue found in the tonsils, spleen, lymphatic 

 glands, and allied structures. It consists of a very fine 

 network of fibrils, around which are cells of various sizes. 



30, Cartilage. Cartilage, or gristle, is 

 a tough but highly elastic tissue. Under 

 the microscope it is seen to consist of a 

 matrix, or base, in which nucleated cells 

 abound, either singly or in groups. 



Cartilage has sometimes the appear- 

 ance of fine ground glass, when it is 

 spoken of as hyaline. This kind of car- 

 tilage forms the early state of most of 

 the bones, and is also a permanent 

 coating for the articular ends of long 

 bones. 



In other cases the matrix is almost 

 replaced by white fibrous tissue. This 

 is called white fibro-cartilage, and is found 

 wtiere * great strength and a certain 

 amount of rigidity are required, as in the 

 disks between the bodies of the verte- 



, . . r n , * . . , i, hyaline cartilage; 2. 



brae, in the interior of the knee joint, in white fibr o-c a rtiiage ; 

 the wrist and other joints, and also in the 

 lining of the grooves for various tendons. 



Again, there is between the cells a meshwork of yellow 

 elastic fibers. This is called yellow or elastic fibro-cartilage, 

 and is found in the gristle of the external ear, in the 

 cartilage of the Eustachian tube, in the epiglottis and in 

 other parts of the larynx. 



FIG. 10. Longitudi- 

 nal Section of Car- 

 tilage. 



3, white fibrous con- 

 nective tissue. 



