192 DISEASES OF THE HORSE’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 
Fic. 99.—HorizontaL SECTION oF A CORN. 
The section cut at about the base of the papille of the sensitive sole. 
w, Papille, with horn-cells surrounding them; 0, interpapillary or inter- 
tubular horn ; ¢, hollow spaces in the intertubulay material filled with 
blood ; a, 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 immediately beneath it. It may, 
however, proceed from injury to the vessels of the lamine 
either of the bars or of the wall. In this case the ecchy- 
\ 
