to inflammatory tissue adhesions between the flexor perforans and the
perforatus, and to a partial destruction of the synovial membrane of the
sheath.

If, in spite of the antiseptic irrigations, the fistula persists, then
nothing remains but to resort to excision of the aponeurosis, as described
on p. 222.

_When Necrosis of the Lateral Cartilage is present_.--In this case we may
at first try the ordinary treatments of poulticing; and blistering, of
antiseptic caustic injections, and of plugging. In some cases a cure is
effected. Should these fail, however, and we intend to see the finish of
our case, then operative measures must be determined on. This means cutting
down upon the diseased cartilage, and either removing the necrosed portion,
or excising the cartilage in its entirety.

The latter method is seldom practised in this country. As it is the most
radical of the two, however, we shall describe it here first.

_Extirpation of the Lateral Cartilage_.--The operation of extirpating the
lateral cartilage is by no means a new one, being introduced, according to
Zundel, by the senior Lafosse in 1754. It consisted in removing a portion
of the wall by grooving and stripping it, and of excising the exposed
cartilage by means of a sage-knife.

As to what portion of, and how much of the horn of, the quarter should
first be removed, and as to what particular direction each groove should
take, opinion among the older writers varied considerably. This we know
now is not an important matter, and it is sufficient to say that the first
preliminary is a thinning down of the horn of the quarter with the rasp
over the position occupied by the cartilage. At the present time there are
two or three modifications of the operation as originally introduced.
In all, however, the preliminary steps are the same. We shall therefore
describe them collectively, as applying correctly to either of the three
methods of operating we are about to show.

_Preparation of the Subject and Preliminary Steps in the Operation_.--On
the day previous to the operation the horn of the wall immediately over the
cartilage must be so thinned with a rasp as to yield readily to pressure
of the thumb in any position. It should be so thin as to only just avoid
wounding the sensitive structures below.

The whole of the foot must then be thoroughly cleansed, and rendered as
nearly aseptic as possible. The use of warm water, soap, and a stiff brush
is the read