224 MANUAL OF MODERN FARRIERY 



liquity of the pastern, producing a weakness in the 

 joint, and liability to sprain of the back sinew, 

 described at page 95. The foot itself will be weak, 

 and have a general tendency to that hidden lame- 

 ness called "the navicular joint disease," particular- 

 ised at page 139. 



The general thickness of the crust in front is 

 somewhat more than half-an-inch, becoming gradu- 

 ally thinner towards the quarters and heels. This 

 will show the necessity for shoeing-smiths being 

 adepts in driving the nails, seeing the small space 

 for that purpose, and more especially behind. The 

 crust is thinner and a little higher in the inner 

 than the outer quarter. This is another beautiful 

 provision, because, being placed under the inner 

 splint bone, more of the weight rests on the inside 

 than the outside, consequently it is enabled to ex- 

 pand more, and thus by its elasticity assists in 

 lessening concussion. When, therefore, expansion 

 is prevented by the inner quarter being nailed 

 firmly to the shoe, corns, contraction, and sand- 

 crack are induced. The crust is not liable to much 

 variation in thickness, as will be seen by a reference 

 to Plate vi, fig. 10, u and v, and c in fig. 9, until 

 near the top, at the coronet, or where the horn 

 of the hoof unites with the skin of the pasterns, 

 where it becomes abruptly thin, as will be seen 

 on a reference to s, in fig. 10. Here it appears as 

 if scooped out, and here also its colour and consist- 

 ence are changed, and it appears like a continuation 

 of the skin. This thin portion is called the coronary 

 ring, r, fig. 10, which covers a thickened prolonga- 

 tion of the skin called the coronary ligament, c, in 

 fig. 9. This extension of the skin is supplied with 

 numerous densely set blood - vessels, connected to- 



