ANATOMY AND PHYSIOLOGY OF THE HORSe’s FOOT. 425 
the fibrous element predominating greatly over the cartila- 
ginous — a circumstance which renders them more vascular, 
and also, it would appear, less disposed to become the seat of 
bony deposition. 
The Coronary Cushion . — I have given this name to an 
elastic structure that somewhat readily attracts the eye on the 
removal of the hoof from the foot, standing out, as it does, 
boldly from around the upper part of the organ, in the form 
of a thick rounded prominence, or cornice. 
This body, like so many other parts of the horse’s foot, has 
received a variety of names, more or less indicative of its 
function or physical characteristics: such as “cutidure” or 
“ cutis-dura,” from its relations with the skin of the pastern ; 
“ coronary ligament,” from its ligamentous-like density ; 
ce coronary substance,” an indefinite term ; “ coronary band,” 
quite as indefinite ; “ matrix of the hoof,” because of its being 
the chief secretory organ of the wall of the hoof ; “ bourrelet” 
by French, and “ fieischkrone 33 by German veterinarians. 
Besides its function as the secretor of the hoof wall, which 
will be noticed hereafter, there can be no doubt whatever that 
it assumes a very prominent part in the elasticity of the foot. 
Situated at the upper margin of the os pedis, the pyramidal 
process of which forms its highest point, and surrounding the 
joint resulting from the union of that bone and the second 
phalanx, this wide convex prolongation is most extensive in 
front, slightly contracts as it passes round towards the points 
of the heels, where it again assumes large dimensions in con- 
stituting an acute angle at the lower extremities or bulbs of 
the lateral cartilages; after which it rapidly diminishes, and 
finally disappears in its course along the concavity of each 
wing of the pedal bone. The space between the two angles 
of the heels is occupied by the thick bulbs of the cartilages, 
which here appear to be a continuation of this coronary 
cushion, so intimately are the component parts of the elastic 
apparatus of the foot eventually blended into one mass. 
The body of this large protuberance is mainly composed of 
dense fibrous tissue, a modification of that which constitutes 
the substance of the true skin immediately above and in con- 
nection vith it; in the meshes of this tissue, beneath the 
keratogeneous membrane, are large quantities of fat vesicles ; 
the convex anterior, lateral, and posterior portions fit into a 
corresponding concavity excavated on the upper and inner 
border of the hoof wall. 
The colour of the coronary cushion is usually of a bright 
red, owing to its great vascularity; though this is not uu- 
frequently obscured, wholly or in patches, by the presence of 
