PLATE IX. 



OSSELET — CARPITIS — SPLINT. 



(From dried bones in Mr. Field's Museum.) 



Fig. 1 (a, a, a) represents a beautiful specimen of the disease described under the 

 appellation of osselet, at page 257. The osseous tumour upon the inner side 

 of the head of the cannon bone of the near fore leg, from which this drawing 

 was made, is of the magnitude and shape of a very small orange, and exhibits 

 the usual porous rugged aspect of exostoses after maceration and drying. The 

 entire head, as well as the body of the cannon bone to the extent of an inch and 

 a half down, is buried in the substance of the tumour, which likewise extends half 

 way across the front of the bone. 

 A SPLINT {h, h) is exhibited upon the same cannon bone, uniting it firmly and 

 fixedly with the internal splint-bone. It is here situated (in the natural bone) 

 about two inches below the osselet. It will be observed that, below the part 

 invested by the tumour of the splint, the small metacarpal or splint bone runs 

 separate from the large metacarpal or cannon bone, there being in the recent 

 subject between them a fibro- cartilage of an elastic nature. 



Fig. 2 is the head of the cannon bone, represented inFig. 1, with its splint bones still 

 attached, sawn off, and having its articulatory surface turned towards the spec- 

 tator. To adapt it to the space left for it, the figure has been turned with its outer 

 side upward. The upper (i. e. in situ, the outer), two-thirds of this surface, upon 

 which the inferior row of the bones of the knee lie, is smooth and polished, as in 

 health ; but the lower {in situ, the inner) third is in a state of disease. The 

 articulatory surface upon the head of the internal splint bone is crowded with 

 asperities and porosities, in the midst of which, near to the tumour of the osselet^ 

 is one deep rugged excavation. The adjoining (inner) surface of the cannon bone 

 likewise displays similar asperous porosity. This morbid condition of the arti- 

 culatory surfaces is the consequence of carpitis running into ulceration of the 

 articular cartilages and caries of the bones. 



