44 



THE ESSENTIALS OF HISTOLOGY 



larly disposed (b). In the deepest part of the cartilage, next the bone, 

 there is often a deposition. of calcareous salts in the matrix (calcified 

 cartilage, d). 



The disposition of the cells of cartilage in groups of two, four, and 

 so on, is apparently due to the fact that these groups have originated 

 from the division of a single cell first into two, and these again into 

 two, and so on (fig. 52). It would seem that the matrix is formed of 





FIG. 52. PLAN OF THE MULTIPLICATION OF CELLS OF CARTILAGE. 



A, cell in its capsule ; B, divided into two, each with a capsule ; c, primary capsule disap- 

 peared, secondary capsules coherent with matrix ; D, tertiary division ; E, secondary 

 capsules disappeared, tertiary coherent with matrix. 



FIG. 53. DIVISION OF A CARTILAGE-CELL. 



a-A, stages of division of a cell, as seen in the living cartilage of the salamander (the con- 

 nection of the nuclear filaments could not be made out in the fresh condition). , 6, stel- 

 late phase ; f, d, commencing separation of the nuclear filaments ; the further stages of 

 separation are not represented ; e, filaments fully separated into two groups, and a septum 

 beginning to be formed between them ; /, septum completed, seen to be double and con- 

 tinuous with capsules of daughter cells ; g, h, further stages in the formation of the 

 daughter nuclei. 



successive portions, which are deposited around each cartilage -cell as the 

 so-called ' capsules) each newly formed portion soon blending in its turn 

 with the previously formed matrix, whilst a new capsule is formed 

 within it. The division of the cartilage-cell, like that of other cells, 

 is accompanied by a process of karyomitosis. 



