NEW VIEWS OF THE GROWTH OF BONES. 47 



of cartilage corpuscle is still applied. This is the common em- 

 bryonic constitution of cartilage. The fixed character of the 

 cartilage depends upon the after changes which take place in 

 it. If fibro-cartilage be formed, the intercellular or hyaline sub- 

 stance is developed in the form of fibres and the cells disappear 

 altogether. If elastic cartilage, fibres are developed around the 

 cells forming a kind of network. If ossific cartilage, the hya- 

 line substance takes on a stratified arrangement round the car- 

 tilage cells, and in it a new set of corpuscles arc developed, 

 called the bone corpuscles, that are the nuclei of the bone 

 cells, see Fig. 9, of which the microscope has shown in reality 

 all bony structure to consist. As this process is commencing, 

 the cluster of cartilage cells called cartilage corpuscles, become 

 compressed together. The secondary hyaline substance becomes 

 dissolved, transudes through the walls of the parent cell, 

 coagulates round it, and in this state of ajtoblastema as it is 

 called — this basis structure for the growth of other parts — it con- 

 stitutes the proper ossific cartilage. In it arise the bone cor- 

 puscles, called cytohlasts or germs, from which are formed the 

 bone cells. These follow the same mode of development, as 

 the embryonic cartilage cells : that is new corpuscles are 

 forming in the cytoblastema, while those recently produced 

 are growing; the cartilage corpuscles ever more closely com- 

 pressed together disappear; radiated points, nutrient vessels, etc. 

 make their appearance, the nuclei of the bone cells, (corpuscles,) 

 and the cells themselves when completely formed receive depos- 

 its of calcareous salts, and the formation of bone is achieved. 



flexible during life. It does not on boiling yield gelatine like them, but a sub- 

 stance called chondrin, which differs from gelatine in not being precipitated by 

 tannic acid, etc. C. The groups of cartilage corpuscles are now seen completely 

 inclosed by bone cartilage. D. The cartilage corpuscles are here rendered less 

 transparent by the process of resolution that is going on ; the bone corpuscles 

 are at the same time making their appearance in the bone cartilage. E. The 

 cartilage corpuscles are dissolved and partially removed. F. The cartilage cor- 

 puscles have disappeared ; have been absorbed. G. In spongy bones, the spaces 

 occupied by the cartilage corpuscles remain as cells filled with globules of fat. 

 In compact bones the cells are reduced to minute canals, by the growth of bony 

 matter, or they disappear entirely. In Fig. 9, there is a representation of bone 

 in its perfectly formed slate, magnified 450 diameters, and representing the bone 

 cells or corpuscles, with their calcareous canals. 



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