INFLAMMATOEY AFFECTIONS 



285 



and is more or less granular and inclined to break up under 

 mani^Dulation. As a consequence, any rough use of the 

 drawing-knife, or an accidental wounding with sharp flints 

 or stones, leads to exposure of the sensitive structures and 

 local gangrene. 



With the horn of the sole thus deteriorated by reason of 

 excessive and continued pressure upon the parts secreting 

 it, it is not surprising to find that, in many cases, actual 

 penetration of it with the os pedis occurs. It is the anterior 

 portion of the inferior margin of the bone that makes its 



Fig. 123. — Solar Aspect of Foot with Chronic Laminitis, show- 

 ing ITS Abnormal Oval Shape from Before Backwards, and 

 THE Excess of Horn growing from the White Line in the 

 Region of the Toe. 



appearance, and shows itself as a small semicircular white 

 or dark gray line on the sole. 



Exposure of the bone is soon followed by its necrosis, in 

 which case the wound takes on an ulcerating character. 

 From it there is a discharge of pus, black in colour and 

 offensive in smell, and, protruding from the opening, are 

 excessive granulations of the remains of the sensitive sole. 



The 'white line,' so apparent when a normal foot is 

 cleaned with the knife, can no longer be sharply distin- 

 guished from the surrounding horn, while in some cases the 



