DISEASES FROM FAULTY CONFOEMATION 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) suppuratimj. 



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, p>^'edisposin(i 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. 



