194 OSSEOUS SYSTEM. 



ft. It is a chronic inflammation of the bones. 



Q. How does necrosis differ from caries ? 



. In necrosis the hone is dead, in caries it is in dis- 

 ease. 



Q. What bones are most liable to caries? 



#. The spongy bones. 



Q. How many forms are there of exostosis ? 



#. There is one form in which the enlarged bone is 

 perfectly hard, another in which the exostosis is lamellat- 

 ed, and a third in which there is a mixture of fleshy gra- 

 nulations sprouting from the bony disease. 



Q. What is remarkable of the hard exostosis? 



/?. That the affection of the soft parts bears no propor- 

 tion to the extent of the ossification. 



Q. What bones are most liable to exostosis? 



fl. The cranium and tibia. You often see them on the 

 inside of the head and in the pelvis. 



Q. Is there resolution or suppuration in exostosis? 



#. In the hard and lamellated there are neither; but 

 the carneous exostosis accompanies caries, arid this is vas- 

 cular, and there is the termination of the inflammation in 

 suppuration. 



Q. To what is the fragile bone or brittleness owing ? 



#. To a deficiency of gelatine. 



Q. What is the pathology of rickets ? 



A. It is a deficiency of calcareous deposition. 



Q. How is osseous malformation jdivided? 



#. Into congenital and accidental. 



