set up the chronic inflammatory condition leading
to hypertrophy of the horn.

From the position on the os pedis of the indentation made in it by the
keraphyllocele (see Fig. 133) it has been argued that pressure of the
toe-clip is a cause of the new growth. This, we should say, cannot be a
very strong factor in the causation, for, while we admit that the continual
pressure of the clip, and the heavy hammering that sometimes fits it into
position, is likely to set up a chronic inflammatory condition of the
sensitive laminae in that region, we must still point out that the rarity
of keraphyllocele, as compared with the fact that clips are on every shoe,
does not allow of the argument carrying any great weight.

_Symptoms_.--Except under certain conditions this defect is difficult
of detection. As a rule, lameness is not produced by it. In making that
statement we are led largely by the conclusion arrived at by Professor
Walley. This observer noted the fact that ingrowths of horn such as we are
describing nearly always take place in false quarter, or after a sand-crack
has been repaired, and that they commonly occur after the operation of
grooving the wall in the manner we have just shown.

Now, we know that quite often under these circumstances the horse goes
perfectly sound. Thus, while we know that in all probability keraphyllocele
is in existence, we have ocular demonstration that the animal is quite
unaffected by it.

In some cases, however, lameness is present. During the early stages of
the growth's formation it is but slight, increasing as the keraphyllocele
enlarges. Should this be the case, other symptoms present themselves.
The coronet is hot, and tender to the touch, sometimes even perceptibly
swollen, and percussion over the wail is met with flinching on the part
of the animal. In other cases one is led to suspect the condition by
the prominence of the horn of the wall of the toe. This is distinctly
ridge-like from the coronet to the ground, while on either side of it the
quarters appear to have sunk to less than their normal dimensions. We
believe this to be an illusion, as a ridge of any size at the toe readily
gives one the impression of atrophy behind it, without this latter
condition being actually present.

Should this ridge-like formation and the accompanying symptoms of pain and
lameness occur after repair of a sand-crack, then keraphyllocele may, with
tolerable certainty, be diagnosed. When thes