OP THE SKELETON. 405 



other times, the adhesion of the articulation remains cellular 

 or fibrous, with a little mobility. Sometimes the destroyed 

 cartilage is reproduced. At other times it is replaced by the 

 transformation of the subjacent bony plate into ivory or ena- 

 mel. In cases of this kind spontaneous luxation of the bones 

 sometimes occurs. 



1 have seen a singular displacement of the hip-joint, depend- 

 ing no doubt upon chronic inflammation. In this case the 

 upper part of the articular cavity seems to have yielded to the 

 pressure of the head of the femur, after having been softened. 

 The cavity, which has become oval, is greatly elongated and 

 hollowed out at its upper part, where it lodges the head of the 

 femur, while the lower part of the same cavity which lodged 

 it before is contracted and superficial. I have observed this 

 change sometimes on one side only, and sometimes sym- 

 metrically produced on both sides at once. 



640. All the diseases of the diarthrodial articulations be- 

 long to each or to several of the parts of which they are formed, 

 to their serous membranes, their cartilages, their ligaments, 

 and to the articular parts of the bones. 



SECTION III. 



OP THE SKELETON. 



641. The skeleton is the aggregate of all the bones con- 

 nected with each other by the articulations. It is called na- 

 tural, when the bones are kept together by their proper liga- 

 ments, and artificial, when the bones are united by substances 

 foreign to the organization. 



It constitutes a symmetrical whole,* which has the form and 



and Elbow. London, 1783. Moreau, De la Resection des Os. &c. Paris, 

 1816. J. Jeffray. Cases of the Excision of Carious Joints, by H. Park and 

 P. F. Moreau, with observations. Glasgow, 1806. Wachter. Diss. de JLr- 

 ticul. Extirp. Groningue, 1810. Roux, De la Resection, &c. Paris, 1812. 

 * Loschge. De Scekto Hum. Symmetrico, &c. Erlang. 1795. 



