plantar cushion, the pyramidal body, the anterior portion of the plantar
surface of the os pedis, and over the anterior face of the same bone. In
turn, as the human foot with its sock is covered by the boot, this is
encased by the hoof, the formation of which we shall study later.

To expose the membrane for study the hoof must be removed. This may be done
in two ways. By roasting in a fire, and afterwards dragging off the horny
structures with a pair of pincers, a knife having first been passed round
the superior edge of the horny box. Or by maceration in water for several
days, when the hoof will become loosened by the process of decomposition,
and may be easily removed by the hands. The latter method is less likely
to injure the sensitive structures, and will expose them with a fresh
appearance for observation.

For purposes of description the keratogenous membrane is divided into three
regions:

1. The Coronary Cushion.
2. The Velvety Tissue.
3. The Podophyllous Tissue, or the Sensitive laminæ.

1. THE CORONARY CUSHION. In the foot stripped of the hoof the coronary
cushion is seen as a rounded structure overhanging the sensitive laminæ
after the manner of a cornice. It extends from the inner to the outer bulbs
of the plantar cushion, and is bounded above by the perioplic ring, and
below by the laminæ.

When _in situ_ it is accommodated by the _Cutigeral Groove_, a cavity
produced by the bevelling out of the superior portion of the inner face of
the wall of the hoof. Its superior surface is covered by numerous elongated