INFLAMMATOKY AFFECTIONS 301 



symptoms of pain and lameness occur after repair of a sand- 

 crack, then keraphyllocele may, with tolerable certainty, be 

 diagnosed. When these outward signs are wanting, how- 

 ever, and the true nature of our case is a matter of mere 

 conjecture, a positive diagnosis may still be made at a later 

 stage — that is, vv^hen the abnormal growth of horn reaches 

 the sole. In this case either there is met with when paring 

 the sole a small portion of horn, circular in form, distinctly 

 harder than normal, and indenting in a semicircular fashion 

 the front of the white line at the toe, or solution of con- 

 tinuity between the tumour and the edge of the sole and the 

 OS pedis takes place, and the lameness resulting from the 

 ingress of dirt and grit thus allowed draws attention to the 

 case. 



Pathological Anatomy. — With the sensitive structures 

 removed from the hoof by maceration or other means, these 

 growths are at once apparent. They may occur in any 

 position, but are usually seen at the toe, and they may 

 extend from the coronary cushion to the sole, or they may 

 occupy only the lower or the upper half of the wall. In 

 places the tumour (or ' horny pillar ' as the Germans term 

 it) is roughened by offshoots from it, and does not always 

 exhibit the smooth surface depicted in Fig. 13'2. Commonly, 

 the horn composing the new growth is hard and dense. 

 Sometimes, however, it is soft to the knife, and is then 

 found to be itself fistulous in character, a distinct cavity 

 running up its centre, from which issues a black and 

 offensive pus. 



In a few cases the sensitive lamina^ in the immediate 

 neighbourhood are found to be enlarged, but in the majority 

 of cases atrophy is the condition to be observed. Not only 

 are the sensitive structures found to be shrunken and 

 absorbed, but the atrophy and absorption extends even 

 to the bone itself (see Fig. 133). This latter is a result 

 of the continued pressure of the horny growth, in a well- 

 marked case ending in a sharply-defined groove in the 

 OS pedis in which the keraphyllocele rests. The fact that 

 the softer structures, and even the bone, thus accommo- 



