DISEASES FROM FAULTY CONFORMATION 183 
the swollen structures within the non-yielding hoof, and 
moistness as a result of the inflammatory exudate. 
In a severe case the inflammation is complicated by the 
presence of pus. 
Classification.—Putting on one side the classification of 
Lafosse (natural and accidental), as perhaps wanting in 
correctness, seeing that all are accidental, and disregard- 
ing the suggested divisions of Zundel (corn of the sole and 
corn of the wall) as serving no practical use, we believe, 
with Girard, that it is better to classify corns according to 
the changes just described. 
Following his system, we shall recognise three forms : 
(1) Dry, (2) moist, (3) suppurating. 
The dry corn is one in which the injury has fortunately 
been unattended with excessive inflammatory changes, and 
where nothing but the coloration imparted to the horn 
by the extravasated blood remains to indicate what has 
happened. 
The moist corn is that in which a great amount of in- 
flammatory exudate is the most prominent symptom. It 
indicates an injury of comparatively recent infliction. 
The suppurating corn, as the name indicates, is a corn in 
which the inflammatory changes are complicated by the 
presence of pus. 
Causes.—The causes of corns we may consider under two 
headings—namely, predisposing and exciting. 
Predisposing Causes.—By the heading of this chapter 
we have already intimated that corns are due to faulty con- 
formation of the foot. It is, therefore, merely a descrip- 
tion of such shapes of foot as favour their formation that 
will need mention here. 
The wide, flat foot, with low heels, may be first con- 
sidered. Here the posterior portions of the sole, those 
portions between the wall and the bars, fall very largely in 
the same plane as the wearing surface of the bars and the 
wall. As a consequence, these portions of the sole are more 
prone to receive injury from stones and rough roads and 
from the pressure of the shoe. 
