OSSEOUS CACHEXIA. 



17 



a spongy appearance. They diminish in density. These changes 

 correspond to the stages of eccentric rarefying ostitis and osteoporosis 

 of German authors. 



The flat bones often show well-marlied periostitis, but the great 

 thickening sometimes seen in certain of the bones of the head appears 

 to be the result of a special osteo-periostitis. It is quite certain that 

 the disease is due to something more than a mere want of mineral 

 constituents in the bone, and poverty in this respect certainly does 

 not explain the hypertrophic changes. The nutrition of the bones as 

 a whole is disturbed, resulting in alterations both in the ossein and 



Pie. 8. Transverse section through the middle region of the face in a pig 



suffering from osseous cachexia. 



in the mineral salts, the whole process being accompanied by symptoms 

 of osteo-periostitis. 



The fractures wLich occur so frequently during the osteoclastic phase 

 have well-marked peculiarities. The extravasation of blood is trifling, 

 and no callus forms, even when the ends of the bones are immobilised 

 by external aid ; if the ends are left free, they soon become worn and 

 polished by rubbing against one another. 



In the neighbourhood of the articulations and ligamentous msertions 

 the periosteum soon undergoes change, and it is not uncommon to find 

 sub-periosteal and intra- osseous extravasations of blood. 



Germain has also noted in horses the disappearance of the mterver- 

 tebral and articular cartilages, and the frequent occurrence of anchylosis, 

 true or false. 



