14 ON THE NAVICULAR DISEASF. 



qiient inllammation liappen either to the synovial 

 inenibiaiie lining the flexor tendon where it articu- 

 lates with the navicular bone, or to the synovial 

 membrane covering the corresponding surface of 

 the bone. To prove the decided character of this 

 disease, I can confidently aflfirm, that it is uniformly 

 confined to the under surface of the navicular bone, 

 where it articulates with the flexor tendon, and 

 never afiects its upper articulating surface, where 

 it assists in forming the coffin joint with the coffin 

 and small pastern bones. 



I have frequently seen, in long standing cases of 

 the navicular disease, not only all the cartilaue of 

 the inferior surface of the bone ulcerated, but also a 

 material part of this small bone absorbed — indeed 

 almost annihilated ; and yet its upper surface, just 

 described, sound, with the cartilage entire, and sy- 

 Coffin joint novial membrane (juite perfect. The truth is, that, 

 of the anckntin thcsc cascs of groggy or chronic foot lameness, 



inj^it: theterin tlic coffiu joiut is ncvcr affcctcd ; and I would con- 

 become obso- 



lete. fidently assert that it never has been aflfected, ex- 



cept in those occasional instances of extreme vio- 

 lence which may have been tantamount to a fiac- 

 ture, and terminated in leaving the leg and foot to- 

 gether a mere stump, by a general anchylosis of all 

 the joints below the upper pastern. 



Now to return to the important fact, daily and 

 hourly before our eyes, of the soundness of many 

 fast-working horses whose feet are contracteil. [ 



