In other cases, however, the necrosis has spread deeper. Caries of the os pedis, of the lateral ligaments of the pedal-joint, or of the lateral cartilages, is a result. When this occurs the exuding discharge from the coronet becomes thinner and more putrescent, and its feel, when rubbed between the fingers, sometimes gritty with minute fragments of broken-up bone. Here, unless operative measures prevent it, necrosis soon spreads deeper still. The deeper portions of the os pedis become affected. The capsular ligament of the joint is penetrated by the suppurative process, and a condition of septic arthritis results. The cavity of the joint becomes more or less tensely distended, according to the amount of drainage present, which in this case is almost nil, with matter in a state of putrescence. As a consequence, the surrounding ligaments become softened and yield, and the articular surfaces displaced. The articular cartilages also suffer, become necrotic in patches, and frequently wholly destroyed. The end result is one of anchylosis of the joint and permanent lameness. _Prognosis_.--With the ordinary dry corn a return to the normal may nearly always be looked for. Similarly, with moist corn, and even with careful treatment of the suppurating variety, the same favourable termination may be looked for and promised. What cannot so safely be assured is that a relapse will not occur. In other words, the extent of the injury, no matter how serious, does not often offer anything that cannot be overcome by Nature and careful surgery; but the conformation of the animal does. A vicious predisposing conformation once there is there always, and although the injury resulting from it may easily give way to correct treatment, the same injury is bound to re-occur when the animal is again put to work. Although with care suppurating corn, like other cases of suppuration within the hoof, may yield to treatment, the owner of the animal should, nevertheless, be warned that the condition is a serious one, especially should the joint become affected. It may so happen, as sometimes in fact it does, that the animal may die as a result of the infective fever so set up. From no surface in the body can absorption take place quicker than from the synovial membrane of a joint. So soon, therefore, as this membrane comes in contact with septic material, so soon does a severe septic fever make its appearance. The septic matter has gained the blood-stream, and the patient succumbs to septic poisoning. Apart from death occurring naturally, the changes taking place in the joint in the shape of bony growths or of actual anchylosis may be so severe as to render the animal useless, and slaughter may have to be advised.