DISEASES OF THE FOOT 



161 



bars is a wedge-sliaped mass of rather soft horny tissue that 

 projects forward into the sole. This is the foot jjad or horiiy 

 frog. It is divided into two lateral portions by a medium cleft. 



The coronary cushion projects into the upper border of 

 the wall. It is covered with vascular papillse which secrete the 

 horny fibres that form the wall. The vascular lamince are leaf- 

 like projections, the sides of which are covered by secondary 

 leaves. Honu/ laminar, arranged the same as vascular laminar, 

 line the wall. These tAvo 

 structures are so fir m 1 y 

 united that it is impossible 

 to tear them apart without 

 destroying the tissue. The 

 velvety tissue covers all of 

 the inferior surface of the 

 foot, with the exception of 

 the bars. As the name indi- 

 cates, its surface is covered 

 liv vascular papillir that re- 

 semble tlie ply on velvet. It 

 is firmly united to the horny 

 sole which it secretes. 



The lateral cartilages are 

 attached to the posterior 

 angles of the pedal bone. They are flattened from side to side, 

 and the portion that projects above the coronary cushion may 

 be felt by pressing on the skin that covers it. The plantar 

 cushion is a wedge-shaped piece of tissue formed by interlacing 

 connective-tissue fibres and fat. It is limited on each side by the 

 lateral cartilages. Its inferior face is moulded to the frog. 



The bony core formed by the last bone of the digit and the 



coffin bone was described briefly with the other foot bones. A 



very important bursa, because it is so frequently inflamed in 



coffin-joint lameness, facilitates the gliding of the flexor tendon 



11 



Fig. 37. 



-Foot showing neglect in trim- 

 ming wall. 



