192 DISEASES OF THE HOKSE'S FOOT 



sufficiently large, the horn fibres in the immediate vicinity 

 also are stained. It is this stain in the horn that is the 

 direct evidence of the injury, and is itself popularly known 

 as the corn. It may vary in size from quite a small spot 

 to a broad patch as large as half a crown, while its colour 

 may be a uniform red, or a mottled red and white. The 



Fig. 99.— Horizontal Section of a Corn. 



The section cut at about the base of the papillae of the sensitive sole. 



a, Papillce, with horn-cells surrounding them ; h, interpapillary or inter- 

 tubular horn ; c, hollow spaces in the intertubular material tilled with 

 blood ; d, a papilla and its surrounding horn-cells filled with blood. 



microscopic changes in this connection are illustrated in 

 Fig. 99. 



Ordinarily, this ecchymosis of the horny sole is due to 

 injury of the sensitive sole {mmcd'iately heneatJi it. It may, 

 however, proceed from injury to the vessels of the laminae 

 either of the bars or of the wall. In this case the ecchy- 



