DISEASES OF HORSES AN*) CATTLE. 237 



Beneath these substances are the hard structures, 

 viz., the coffin bone, navicular, and the oscorone 

 (lower pastern). These bones are held together 

 by ligaments, and are clothed by the sensitive sub- 

 stance mentioned. The lateral cartilages are two 

 thin plates of clear cartilage in the middle, and a 

 mixture of fibers and cartilage toward the bor- 

 ders. They are attached to the wing of the coffin 

 bone, pass down over the sensitive frog, and pro- 

 ject upward to the coronary band. They act as 

 braces to the heels. 



The Sensitive Laminae. — This is continuous 

 with the coronary band, and is attached to the cof- 

 fin bone by a dense fibrous membrane. It is com- 

 posed of a number of very highly organized plates, 

 composed largely of blood vessels, nerves, and lym- 

 phatics, held together by a very fine network of 

 fibrous tissue, and is attached to the horny lam- 

 inae interposed between the plates. This is the 

 most sensitive structure of the body, and is the 

 part affected in founder. 



The Sensitive Sole. — This is continuous with the 

 sensitive laminae and frog, and is firmly attached 

 to the inferior surface of the coffin bone. Like the 

 sensitive laminae it is made up of a highly vascu- 

 lar, fibrous membrane, and is covered by the villi, 

 which secretes the horny sole. 



The Sensitive Frog, — This is situated beneath 

 the horny frog, and is made up of an intermixture 

 of yellow fibro-cellular tissue of a peculiar elastic 

 nature, and has been described as fat. It is not 

 nearly so sensitive as the structures just men- 



