266 RINGBONE. 



particular, is rather an unlikely part to be struck. After inflam- 

 mation from any cause, even after that produced by a common 

 blister, very often, we know, an enlargement of the pastern will 

 be left ; and though this is not called ringbone, it may be regarded 

 as something extremely analogous to it. 



In Nature, ringbone is but a species of exostosis. A bony 

 tumour, which in one situation constitutes ringbone, in another 

 constitutes splint, in another spavin. Yet the three differ, as well 

 in their origin and in their effects. Ringbone has an external 

 origin ; and though it mnry from spreading interfere with the 

 motion of a joint, still does it not, that we know of, produce any 

 affection of the synovial membrane. Spavin, on the contrary, 

 seldom confines itself to the external or ligamentary tissues, but 

 affects the synovial membrane as well. And splint originates in 

 the very joint — ihe Jibro-cartiLaginous — which it afterwards blocks 

 up and grows from. 



Ringbone is either a ligamentary or a periosteal affection, or 

 both. From the situation in which we commonly find it, and from 

 the causes which are known to give rise to it, we believe it usually 

 to be ligamentary in its beginning ; though, when once formed, and 

 given to spread, no tissue, save the tendons, escapes conversion to 

 contribute to the osseous mass ; and even the tendons themselves 

 have been known to become partially ossified. In fact, when the 

 exciting cause has been great, or when there exists an evident 

 proneness in the constitution to ossific action, such is the extensive 

 and varied form ossification takes on, that we can hardly say where 

 it will make an end, so long as any soft tissues yet remain to be 

 converted. Writing in the year 1823 on this subject, with 150 

 morbid specimens of the kind upon the table before us, we find we 

 were led at the time to make the following remarks : — 



" By far the most common seats of (ossific) disease are the pas- 

 tern, coronet, and coffin bones. Out of the (said) 150 specimens 

 there are 



" 5 of complete anchylosis of the fetlock joint. 



" 40 of complete anchylosis of the pastern joint. 



" 18 of complete anchylosis of the coffin joint. 



" The others are either simply encrusted, more particularly 



