snared by a fine,
spring wire passed as a loop through a fine tube (like a teat tube open at
each end) and introduced into the teat. When this can not be done, the only
resort is to cut in and excise it while the cow is dry.

THICKENING OF THE MUCOUS MEMBRANE AND CLOSURE OF THE
MILK DUCT.

As a result of inflammation extending from without inward, a gradual
narrowing of the milk duct may occur from thickening and narrowing of its
lining membrane. This may be limited to a small area near the lower end, or
it may extend through the whole length of the teat. The stream of milk
becomes finer and finer until it finally ceases altogether, and a firm cord
is felt running through the teat. If the constriction is only at the
outlet, the teat may be seized and distended by pressing the milk down into
it from above, and an incision may be made with a sharp penknife in two
directions at right angles to each other and directly in the original
opening. The knife should be first cleansed in boiling water. The opening
may be kept from closing by a dumb-bell shaped bougie of gutta-percha (Pl.
XXIV, fig. 5) or by the spring dilator. If the obstruction is more extended
it may be perforated by Luethi's perforating sound. (Pl. XXIV, fig. 1A and
1B.) This is a steel wire with a ring at one end, and at the other is
screwed on to the wire a conical cap with sharp cutting edges at the base,
which scrapes away the thickened masses of cells as it is drawn back. This
may be passed again and again to enlarge the passages sufficiently, and
then the passage may be kept open by wearing a long, dumb-bell bougie, a
thick piece of carbolized catgut, or a spring dilator. If the passage can
not be sufficiently opened with the sound it may be incised by the hidden
bistoury. (Pl. XXIV, fig. 2.) This is a knife lying alongside a flattened
protector with smooth, rounded edges, but which can be projected to any
required distance by a lever on the handle. The incisions are made in four
directions, as deep as may be necessary, and the walls then can be held
apart by the spring dilator until they heal. In case the constriction and
thickening of the canal extend the whole length of the teat, it is
practically beyond remedy, as the gland is usually involved so as to render
it useless.

CLOSURE OF THE MILK DUCT BY A MEMBRANE.

In this form the duct of the teat is closed by the constriction of its
lining membrane at one point, usually without thickening. The c