MICROSCOPICAL CHANGES AFTEK ' CORN.' 



389 



seats. According to their severity and seqneke corns may be 

 divided into several varieties. 



(1) Slight bruises lead to distortion of the horny lamina^ 

 and secondary laminae (fig. 364, tl and c) and to superficial in- 

 flammation of the corium with exudation of sero-sanguineous 

 fluid, which causes a yellowish, waxy or yellowish-red colora- 

 tion. Extravasation of blood produces a red or bluish-red 

 colour. The fluid exuded is again absorbed, leaving the spot 

 dry, hence the name * dry corn.' Lameness is seldom associ- 

 ated with this form. 



(2) Severe bruising and the entrance of pyogenic organisms, 

 lead to inflammation and suppuration, the condition termed 

 ' suppurating corn.' Failing artificial paths of escape through 

 the horn, the abscess enlarges in the direction of least resist- 

 ance, i.e., upward between the sensitive and horny laminse 



Fig. 365.— Transverse section of horny and sensitive wall from case of corn of the wall. 

 X 24. a, horn wall ; b, horny laminae ; c and d, degenerated horn ; e, sensitive wall ; 

 /, space produced by formation of pus; g, shrivelled sensitive lamina;; h, distorted 

 horny laminae. 



(fig. 365, f), and finally breaks through at the coronet. In 

 corns of the sole the sensitive and horny soles are separated 

 to a greater or less extent, and in corns of the bar suppura- 

 tion may even extend to tlie plantar cushion. Suppurating 

 corns often produce great pain and lameness. 



(3) When mechanical irritation is continually renewed, the 

 corn becomes permanent. Organic changes occur in the 

 corium and hoof and sometimes in the pedal bone itself. The 



