dvantage, the veins must be provided with valves, and valves of no
mean strength. These we know to be absent. It is here that the lateral
cartilages and the elastic substances of the coronary and plantar cushions
step in to supply the deficiency.

At the time when weight is placed upon the foot (with, of course, a
tendency to drive the blood upwards in the limb), and, therefore, the time
when a valvular apparatus is needed to retain the fluid in the foot, we
find the wanting conditions supplied by the pressure outwards of the
plantar cushion compressing the large plexuses of veins on each side of the
lateral cartilages, to which plexuses, it will be remembered, the bulk
of the venous blood from the foot was directed. A more perfect valvular
apparatus, automatic and powerful, it would be difficult to imagine.

E. GROWTH OF THE HOOF.

We will conclude this chapter with a few brief remarks on the growth of
the hoof. That the rate of growth is slow is a well-known fact to every
veterinarian, and it will serve for all practical purposes when we state
that, roughly, the growth of the wall is about 1/4 inch per month. This
rate is regular all round the coronet, from which it follows that the time
taken for horn to grow from the coronary edge to the inferior margin
will vary according as the toe, the quarters, or the heels are under
consideration.

As might naturally be expected, the rate of growth will depend on various
influences. Any stimulus to the secreting structures of the coronet, such
as a blister, the application of the hot iron, or any other irritant,
results in an increased growth. Growth is favoured by moisture and by
the animal going unshod, as witness the effects of turning out to grass.
Exercise, a state of good health, stimulating diets--in fact, anything
tending to an increased circulation of healthy blood--all lead to increased
production of horn. With the effects of bodily disease and of ill-formed
legs and feet on the wear of the hoof, and the growth of horn, we shall be
concerned in a future chapter.

CHAPTER IV

METHOD OF EXAMINING THE FOOT

As a general rule, it may be taken that most diseases of the foot are
comparatively easy of diagnosis. When, however, the condition is one which
commences simply with an initial lameness, the greatest care will have to
be exercised by the practitioner.

What remarks follow here should rightly be confined to a treatise on
lameness. This much, however,