RINGBONE. 267 



around their extremities, with layers of new bone, or are variously 

 deformed by exostoses of different shapes, many of which are very 

 large, and several of them confined to one side. Upon one of the 

 pastern bones a complete osseous ring is formed, the result of ossi- 

 fication of the theca of the flexor (perforatus) tendon. In nearly 

 all, the disease appears to have taken its rise at, and to have 

 spread from, the pastern joint ; there being but few specimens in 

 which some (osseous) accretion is not to be observed around the 

 lower end of the pastern hone and the upper one of the coronet hone; 

 which is the kind of deposition that gives rise to ringbone*." 



Here are facts which not only demonstrate the more common site 

 of ringbone, but reflect a good amount of light upon its origin and 

 nature and tendency as well. While the nidus of ringbone appears 

 to be the ends of the two bones concurring to form the pastern joint, 

 there exists a manifest disposition in parts adjacent to take on similar 

 morbid action. Jar or concussion would, as we have endeavoured 

 to shew, be likely to affect this joint, and, in case such amounted 

 to injury, would excite inflammatory action, and this would be 

 followed by ossification. The same result, viz. ossification, would 

 be likely to ensue even though iveakness only was experienced in 

 the joint ; Nature, as we have observed on another occasion, con- 

 solidating the parts to increase their strength. And, as many of 

 the afore-mentioned specimens indicate, to such an extent is this 

 ossification sometimes carried, that pastern, coronet, and foot, are 

 involved in one deformed porous mass of ossification. 



Lameness is not an ordinary Consequence of Ring- 

 bone. Whether the tumour be productive of lameness or not 

 will depend, — First, upon the presence of inflammatory action in 

 it ; Secondly, upon any tension it may create in the periosteum 

 covering it ; Thirdly, upon its proximity to a joint and consequent 

 impediment it may offer to the motions thereof. In general, in young 

 horses, ringbone forms so gradually and imperceptibly, that it is 

 accompanied neither by inflammation nor by tension. It may, 

 however, and frequently does in the course of time, so increase 

 and spread that the pastern joint gets cramped and confined in its 

 action, and ultimately becomes a fixture ; and the consequence is, 

 * " Elementary Lectiares on the Veterinary Art," vol. i, pp. 335-6. 



