ON THE NAVICULAll DISEASE. 21 



tioii of the heels as it is to the occult or partial con- 

 traction. 



A slioht stricture is observable round the middle Constriction of 



° the hoof, and 



of the crust, or towards the upper part. When i'ldtntations. 

 this is not present, there is invariably an indentation 

 or slight falling in of one quarter, generally the in- 

 side quarter, though I have observed this on the 

 outside. 



With regard to ossification of the cartilag-es of 

 the foot, and ossification of portions of the ligaments 

 of the navicular bone, and other bony excrescences 

 within the foot, I would remark, that, having dis- 

 sected so many extreme cases of chronic foot lame- 

 ness of some years' standing, in which I have found 

 all the ravages of this disease limited to a space 

 within the joint not exceeding half an inch square, 

 and unaccompanied with the shghtest disease of any 

 other part of the internal foot, I am induced to con- 

 sider them as mere effects arising out of the navi- 

 cular disease ; and more particularly, as there arc 

 far more groggy feet without the slightest ossifica- 

 tion of the lio^aments of the navicular bone than 

 with them. In short, I think those who have recently 

 described the navicular disease an ossification of the 

 joint, have erred very much ; for it is any thing but 

 an excrescence or exostosis, a great loss or absorption 

 of bone being, in fact, the malady : yet I must ac- 

 knowledge that I have occasionally seen, in recent 

 cases, a few small eminences on the inferior surface 



