DISEASES FROM FAULTY CONFORMATION 193 
mosis of the horny sole may be explained by the fact that 
the escaped blood tends to gravitate to that position. 
When the corn is of long standing, or is due to repeated 
injuries on the same spot, the horn adjacent to the lesion 
becomes hard and dry, and often abnormally brittle, simply 
on account of the inflammatory changes thus kept in con- 
tinuation. This is often seen when attempts are made to 
pare out the corn with the knife. 
Should the injury be seated in the sensitive lamine, then 
the brittle nature of the horn secreted by the injured tissues 
makes itself apparent by the appearance of cracks in the 
4 
Fic, 100.—Inner SURFACE OF THE WALL OF THE QUARTER, SHOWING 
CHANGES IN THE Horny LAMINE BROUGHT ABOUT BY CHRONIC CoRN. 
wall of the quarter. Why this should occur will be readily 
understood by a reference to Fig. 100. 
It will here be seen that the injury to the keratogenous 
membrane has led to great interference with the secretion 
of horn from the sensitive lamine. As a result, the regu- 
larly leaf-like arrangement of the horny lamine has been 
largely broken up. Certain of the lamine are altogether 
wanting, while others are broken in their length and 
rendered incomplete. With this condition there is always 
more or less contraction of the quarter. 
Microscopic examination of the structures involved in 
such a case reveals the fact that with the contraction is an 
13 
