178 OSSEOUS SYSTEM, 



*fl. It is fibrous. The fibres being differently arranged 

 so as to constitute the loose or cellular, and the compact, 

 bony structure. 



Q. How is the cellular bony structure formed? 



/?. Unknown in the first periods of ossification, the 

 cells appear in consequence of the absorption of the solid 

 mass of cartilage, and in its place are deposited by exha- 

 lation transverse bony fibres, which, by interlacing in 

 every direction, and no more gelatine being thrown out, 

 leave the cavities which are the cells of bones. 



Q. Can you present a clear illustration of your last an- 

 swer? 



Jl. The os ethmoides is at one period a solid cartilage, 

 but under the laws and in the process of ossification, the 

 interlacing bony fibres are exhaled, and the cartilage ab- 

 sorbed leaving cells. 



Q. Do the cells communicate with each other? 



*#. Conclusive experiments prove that the cells through- 

 out the interior of a bone communicate universally. 



Q. How does the compact texture of bones differ from 

 the cellular texture ? 



*#. The fibres of the compact texture are in dense juxta- 

 positipn. 



Q. How do these compact fibres run in the long, flat, 

 and short bones? 



*#. These bony fibres are longitudinal in the long, radi- 

 ated in the flat, and run in every direction in the shortbones. 



Q. Do the fibres of this texture, in the apophyses, pur- 

 sue the same direction as in the main bone? 



#. They do not; in some apophyses they are longitu- 

 dinal, in others the course is entirely irregular. 



