404 THE HORSE. 



may be acute or chronic) of the parts between the crust or wall 

 and the pedal bone, including the laminae, whence the name by 

 which it is now distinguished. These parts are supplied with a 

 profusion of blood-vessels (see page 294), and when inflammation 

 is set up in them, the progress which it makes is rapid, and the 

 constitutional disturbance is unusually great, owing probably to 

 the want of space for the swelling which accompanies all inflamma- 

 tions, and especially 0/ vascular substances. The causes are either, 

 1st. Localization of fever, whence the name " fever in the feet/' 

 2d. The mechanical irritation of hard roads upon feet not accus- 

 tomed to them ; and 3d. Long confinement in a standing position 

 on board ship. When it is recollected that in our system of shoe- 

 ing, the laminae are made to support the whole weight of the body 

 in consequence of the shoe being in contact with the crust only, it 

 can only occasion surprise that this disease is not more frequent. 

 Nature framed the horse's foot so that an elastic pad should inter- 

 pose between its back parts and the ground, intending that the 

 edge of the crust should take its share, but not all of the weight. 

 The laminae are therefore called upon to do far more than their 

 structure is designed for, and when there is the slightest weakness 

 or tendency to inflammation, they are sure to sufier. Acute lami- 

 nitis is not very often met with, because horsemen are aware of 

 the risks they run, and take their measures accordingly; but the 

 chronic form is common enough, and hundreds of horses are more 

 or less lame from this cause. Too often it is not suspected until 

 irreparable mischief is done, the elasticity of the laminae being de- 

 stroyed, and the foot having assumed a shape which utterly unfits 

 it for bearing the pressure of the shoe upon hard roads. When 

 the disease has been going on for a long time, the elastic substances 

 between the laminae and the pedal bone, as well as the fine horny 

 lamellae between them and the crust, lose the property of extension, 

 and the horn of the crust is secreted by nature of a more spongy 

 character, and much thicker in substance, than in health. On 

 making a section of such a foofc, the arrangement of parts will be 

 such as is here delineated in fig. 19, in which 1 is the os suflFraginis, 

 2, the OS coronae, and 3, the pedal bone, with its anterior surface 

 separated from that of the crust (7) by a wide space occupied by 

 spongy matter. Here the toe of the pedal bone projects into the 

 sole and renders it convex, instead of being concave, and correspond- 

 ing with the lower surface of the pedal bone. 



The laminae and elastic substances between them and their 

 contiguous structures no longer suspend the pedal bone to the 

 crust, but the weight falls partly upon the sole by means of the 

 toe of the pedal bone, and partly on the frog, which descends so 

 low that in spite of the thickness of the shoe it touches the ground. 



