CAPPED ELBOW. 323 



capped hock. Over the olecranon of the ulna, the same as over 

 the tuberosity of the os calcis, the skin is hollowed out into a sort 

 of cap; interposed between which and the'bone beneath are several 

 concentric, dense, and yet loose, layers of cellular tissue, which 

 render the cap in every direction extremely moveable, while they 

 admit of free and complete flexion of the elbow joint. And these 

 layers are so arranged that an imperfect sort of cavity, having 

 some resemblance to a bursa mucosa, is formed in the midst of 

 them, which, as in the case of the correspondent formation upon 

 the point of the hock, in the normal state appears to contain nothing 

 beyond a kind of serous vapour, such as is exhaled into the cells of 

 the reticular tissue of the body generally. 



In a State of Disease, however, the exhalation becomes aug- 

 mented to that degree that the vapour condenses into a serous fluid, 

 and as such collects in the cells of the reticular tissue clothing the 

 point of the elbow, stretching the cells, and causing them to break one 

 into another, so as ultimately to form one large pouch, or two or more 

 small ones, for the collected fluid. Capped elbow, therefore, like 

 capped hock, is no more at the beginning than serous abscess, though 

 in time the serous may become changed into solid albuminous deposit; 

 and this, in its turn, take on a suppurative action. Under unusual 

 excitement, from the very first, solid instead of fluid matters will 

 be effused, or there may be a combination of both ; and the solid 

 deposition, unless timely dispersion of the tumour be effected, will, 

 in the course of time, become altered from mere lymphy matter to 

 hard fibro-cartilaginous substance, having a yellowish white as- 

 pect, and looking like what is commonly called callus : the forth- 

 coming change being one of a scirrhous nature. Upon the surface 

 of this scirrhous tumour, now and then, suppurative action W\\\ 

 spring up in places, giving rise to little abscesses, which will burst, 

 and leave behind them ragged nasty-looking sores, leading into 

 sinuses, and evincing little disposition to heal ; in which foul in- 

 tractable condition the tumour may, uncorrected, continue to annoy 

 the animal even for years. Sometimes the tumour is encysted; i. e., 

 is contained within a sac, formed around it by the condensation of 

 the contiguous cellular tissue ; and when this is the case, a simple 

 operation ^ets rid of the enlargement at once. Sometimes, however, 



