WOUNDS 233 



portions of the secreting layer of the keratogenous mem- 

 brane are destroyed, or perhaps only temporarily prevented 

 from fulfilling their horn-producing functions, then corre- 

 sponding cavities in the horn are the result (see Fig. 109). 



(h) Purulent Artliritis. — Only too readily the pus so 

 formed tends to penetration of the articulation and the 

 causation of an incurable arthritis (see ChajDter XII.). 



(c) Necrosis of the Extensor Pedis. — This may arise either 

 as a result of spreading purulent infection of the coronary 



a. 



Fig. 109.— Mesial Section of a Hoof illustrating the Conditions 

 following upon coronitis. 



«, Cavity in tlie lioni of the wall ; h, enlargement of the coronet and the 

 horn of the wall following subcoronary suppuration ; c, cavity in the 

 wall following purulent inflammation of the sensitive lamime ; d, hollow 

 in the horn of the sole consequent upon suppuration of the sensitive sole. 



cushion, or as a result of direct injury immediately over 

 it. The close relation of the terminal portion of this 

 tendon with the pedal articulation, and the incomplete pro- 

 tection from outside injuries here afforded to the joint by 

 the horny box, sufficiently points out the gravity of the 

 condition. 



(rf) Penetration of the Articulation. — This also may be a 

 result either of the inroads made by pus, or of an actual 

 wound. When occurring from the latter, it is seen more 

 often than not in the hind-foot, being there caused by the 



