50 



GAKTILAGE 



matrix about itself, so that the increasing space thus produced 

 between the cells of a group may separate them until they become 

 completely isolated cartilage cells each within its own lacuna. In 

 this way the matrix of the cartilage is produced. The matrix 

 of hyaline cartilage is devoid of fibrous or cellular structure. 



During life, or if the tissue is examined in the fresh state, the 

 cartilage cell entirely fills the lacuna in which it lies. But shortly 

 after death shrinkage of these cells begins, so that after some 



hours a considerable space 

 intervenes between the cell 

 and the wall of its lacuna. 

 It has been supposed that 

 this space was occupied 

 during life by lymph. It 

 would, however, seem more 

 probable that it is partially 

 the result of post-mortem 

 shrinkage of the cell. 



Frequently, and espe- 

 cially in developing carti- 

 lage, concentric lines may 

 be seen surrounding each 

 lacuna. These lines have 

 been described as the " cell 

 capsule." They appear only 

 to indicate the successive 

 layers of material which 

 have been deposited by the 

 cell, and which have fused together to form its surrounding 

 matrix. 



Recent investigations on the development of the connective 

 tissues suggest that cartilage arises from a mesenchymal syncytium 

 in which the matrix is formed from the exoplasm of the syncytial 

 tissue, the cartilage cell representing its endoplasm. The so-called 

 capsule of the cartilage cell would accordingly represent the par- 

 tially modified border line between the original endo- and exo- 

 plasm, and would thus correspond to similar conditions which are 

 observed in other forms of developing connective tissue. 



Cartilage cells frequently contain small droplets of fat, and 

 these may coalesce until the cell is completely transformed into 

 a fat cell. Isolated masses of adipose tissue, resulting from the 



FIG. 52. CELLS AND MATRIX or HYALINE CARTI- 

 LAGE FROM THE WALL OF A LARGE BRONCHUS 

 OF MAN. 



The grouping in pairs and fours, and the ten- 

 dency to produce a so-called " capsule," are espe- 

 cially noticeable. Hernateiu. x 550. 



