212 DISEASES OF THE JOINTS. 



Anatomical character of the Disease. — The capsules of the 

 joint are thickened, and at the same time distended with a 

 large quantity of synovial fluid. At a later stage the fluid 

 is removed by absorption, and the capsular membranes acquire 

 a preternatural density. Some of the normal structures, as the 

 round ligament in the hip, and the semi-lunar cartilages in 

 the stifle-joint, are completely absorbed, if the joint has been 

 long and severely affected. The lateral ligaments of the 

 ginglymoid joints become preternaturally elongated, and new 

 growths, varying in consistence — some being cartilaginous 

 tliroughout, others bony in their centres and cartilaginous 

 at their circumference — are found in and around the affected 

 joints. These are first developed in the synovial membrane, 

 and are almost always attached to it by a slender cord, or 

 by a broad base ; and around the rim of the cotyloid and 

 glenoid cavities additional foreign bodies — called by Adams 

 " addimentary bones " — are usually found deepening and en- 

 larging the " cavities of reception" for the heads and condyles 

 of bones composing the articulations. — (See Photo-lithograph, 

 Plate I., Pig. 2.) The articular cartilages are removed, and 

 their place supplied by an ivory-like enamel — the porcel- 

 laneous deposit — in the hip and shoulder joints, the surfaces 

 of the bones become as smooth, in whole or in part, as an 

 ivory baU. — (See Photo-lithograph, Plate II., Pig. 1.) In 

 the ginglymoid joints the place of the removed cartilage is 

 supplied by means of patches of ivory or porcelain-like enamel, 

 marked out by parallel grooves, hoUowed out in the direction 

 of the movements of extension and flexion. — (See Photo- 

 lithograph, Plate II., Pigs. 3 and 5.) 



I think that I have produced sufficient evidence from the 

 symptoms during life, and the appearances of the bones after 

 death, to prove the similarity, if not the identity, of this dis- 

 ease with the rheumatic gout, or more properly the rheumatoid 

 aflection of the joints of the human being. Wliat veterinary 

 surgeon can have failed to notice the peculiar stiffness of the 

 limbs, and the crackling noise emitted when the joints are 

 moved in some cases of bog-spavin and navicular lameness ? 

 And no one, I am sure, is prepared to deny that the peculiar 

 alterations of structure and the intractable nature of the 

 morbid processes are not due to a diathesis or constitutional con- 

 dition similar to that which in man predisposes to this malady. 



