DISEASES FKOM 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 

 jjare out the corn with the knife. 



Should the injury be seated in the sensitive laminte, then 

 the brittle nature of the horn secreted by the injured tissues 

 makes itself apparent by the appearance of cracks in the 



Fig. 100. — Inner Surface of the AVall of the Quarter, showing 

 Changes in the Horny Lamina 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 laminae. As a result, the regu- 

 larly leaf-like arrangement of the horny laminse has been 

 largely broken up. Certain of the laminae 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 



