8 



for it is an invariable law of tlie animal economy not to 

 continue to unemployed structures the same measure of effi- 

 cient reparation, that is extended to parts, constantly engaged 

 in performing theii* allotted tasks. Tlie shoe restricts or 

 prevents expansion ; while Natiu'e, as the secret influence is 

 called, immediately sets to work, to simplify the apparatus 

 for producing the expansion, which art has thus rendered 

 impracticable, and substitutes for it a new structure, less 

 finely organized, but admirably suited to the altered condition 

 of the parts. 



The wings extend from the body of the bone directly 

 backward, and support the "lateral cartilages" of the foot. 



If the coffin bone of a fore foot be placed upon a flat 

 surface, it will be seen, that the whole of the front of the 

 toe is considerably raised or arched, as if a notch had been 

 cut out of it, giving it almost the appearance of an imperfect 

 bone.'"" I consider this to be one of the numerous provisions 

 of nature for diminishing the concussion, to which the horse's 

 foot is so constantly exposed ; for, if the toe of the bone 

 corresponded exactly with the toe of the hoof, a shock would 

 be communicated to the whole foot, each time it struck 

 against a stone, or other projecting substance ; whereas this 

 intervening space by breaking the connection of the parts 

 tends greatly to impede the transmission of the jar. This 

 conjecture is considerably strengthened by the fact, that the 

 coffin bone of the hind foot, where the jar would be less felt, 

 jiresents no such deficiency at the toe. 



The coronet bone is nearly square ;t its breadth from side 

 ♦Plate 2, fig. 2 t Plate 2, fig. 1. 



