HORN TUMOUK. 213 



the sole as well as on the wall, and the concussion caused by the 

 horse striking his toe into the ground will be diminished, as much 

 as possible, hj the shock being distributed over the broad, rounded 

 surface of the toe of the shoe. 



Horn Tumour {Keratoma) 



is a new growth of horn which, according to Moller, may begin 

 in the coronet or in the sensitive laminae. It takes up its position 



Fig. 71. — Shoe with toe turned up on ground surface, but flat on foot surface. 



between the wall of the hoof and the pedal bone, in w^hich an exca- 

 vation is made, in course of time, by the pressure caused by its pre- 

 sence interfering with the nutrition of the bone at that part. It is, 

 as a rule, found at the toe, and is not always accompanied by lame- 

 ness. If the sole be pared, in a case of horn tumour which has 

 been formed by the sensitive laminae, the white line which marks 

 the union of the wall and sole on the ground surface of the foot, 

 will be found to curve inwards at a point immediately under- 

 neath the tumour; the reason being that the white line which 

 in health marks the surface of union between the wall and sen- 

 sitive laminae, is, in a horn tumour, the inner boundary of this 



