364 
ANATOMY OF THE HOUSE. 
superiorly, by the encircling coronary substance; interiorly, by 
sensitive laminae : consequently, altogether, by the hoof, which 
envelopes both the coronary substance and the laminae. The 
extreme posterior ends of the cartilages incurvate downward and 
backward; but, being overreached by the heels of the sensitive 
frog, any abrupt or exposed termination of them is prevented. 
Around these points also the coronary substance makes its in¬ 
flections upon the sensitive frog, thereby giving them additional 
substance and support. 
Form. —Considered in the detached state, the cartilage in its 
general figure describes an irregular quadrangle, of which the 
supero-anterior and infero-posterior angles are the most project¬ 
ing ; the latter at the same time being incurvated inwards. Ex¬ 
ternally, the cartilage is pretty regularly convex; internally, it 
is unevenly concave, the surrounding border turning inwards 
into the substance of the sensitive frog. The posterior part of 
the cartilage is somewhat thinner than the anterior, and has 
several foramina through it—three or four of large size—which 
transmit vessels to the frog. 
THE FALSE CARTILAGES.—From the inferior and pos¬ 
terior sides of the true cartilages, proceed in a direction forward— 
towards the heels of the coffin-bone—two fibro-cartilaginous 
productions, to which Mr. Coleman has given the name of u in¬ 
ferior cartilages.” If they are to be considered as cartilages, I 
prefer denominating them false; they being, as well in structure 
as in use, different from the real or lateral cartilages. They 
spread inwards upon the surface of the tendo perforans ; become 
united at their inner sides with the superior margin of the sensi¬ 
tive frog ; are covered inferiorly by the sensitive sole; and at the 
same time assist in the support of the sensitive frog. They are 
triangular in their figure, and are arched in the same manner as 
the sole. 
Use .—Their use appears to me to be, to fill up the triangular 
vacant spaces left between the tendo perforans and heels of the 
coffin-bone, thereby completing the surface of support for the 
sensitive frog, and extending that for the expansion of the sensi¬ 
tive sole. Bone in these places must have proved inconvenient 
by more or less impeding the impression upon—and consequent 
reaction of—the sensitive frog. 
The Sensitive Lamina or Lamella . 
So is denominated the laminated, membranous, vascular struc¬ 
ture clothing the wall of the coffin-bone. 
Production. —The sensitive laminae appear to be derived from 
the coronary substance—The one, in fact, seems to be a continua- 
