GROWTH OF CARTILAGE. 



455 



which it is inclosed. This membranous capsule, on the 

 division of the cells which it contains, sends in septa 

 between them, which serve as new envelopes for the 

 young cells, yet in such a way, that even the gigantic 

 groups of cells, which proceed from each of the original 

 cells, are still enclosed in the greatly enlarged parent 

 capsule. 



It .is manifest, that the greater the number of cells 

 which undergo this change, the larger the cartilage will 

 become, and that the height to which any one of us 



Fig. 126. Vertical section through the ossifying border of a growing astragalus, 

 c. Cartilage with smallish groups of cells, p, the layer where the proliferation and 

 enlargement are the most marked along the line of calcification. In the cartilage- 

 cavities are seen, partly complete nucleated cells, partly shrivelled, angular and 

 granular looking bodies (artificially altered cells). The dark mass advancing into 

 the intermmediate substance represents the deposition of calcareous salts, behind 

 which the formation of medullary spaces (m, m, m) and osseous trabeculse [spicula] 

 is here beginning with unusual rapidity. The marrow has been removed ; round 

 the cavities which lie farthest back, the trabeculaa are surrounded by a lighter bor- 

 der of young osseous tissue (produced from marrow.) 300 diameters. 



