ecies during June
and July.

The damage caused by warbles includes injury to stampeding cattle
frightened by the fly, decreased milk flow and diminished growth in
infested animals, and injury to hides, the last item being especially
serious.

_Treatment._--The best method of control known at present is to extract the
warbles from the backs of cattle and kill them. If they are almost ready to
leave the cattle, they may be squeezed from the backs with the fingers.
Forceps are useful in removing the warbles, but it is important to be
careful in extracting warbles not to crush them, as the body juices of
these parasites are sometimes poisonous to cattle if absorbed into their
circulation. In the South herds may be examined in November or early in
December and once a month during the next two or three months. In the North
the first examination may be made six weeks to two months later, with two
or, better, three following examinations at intervals of a month. If this
procedure is carefully carried out there will be a noticeable diminution of
warbles the following year, and if persisted in the warble can be almost if
not completely eradicated. Where an entire community follows up the
practice of removing and destroying warbles, the results are highly
beneficial.

As a result of recent studies by various investigators it appears that the
tiny grubs, newly hatched from the eggs, may gain entrance to the body by
penetrating directly through the skin. Many observers, however, have held
that the eggs or newly hatched larvae are taken into the mouth by the cattle
licking themselves. It is possible, as in the case of several other
parasites, that both modes of infection may occur and that the larvae may
gain entrance to the body either by penetrating the skin or by being
swallowed. From the evidence at present available it seems likely that the
usual mode of entrance is through the skin. Irrespective of the mode of
infection, the larvae evidently wander extensively through the tissues of
the body, developmental stages being found in considerable numbers in the
wall of the esophagus during the fall of the year. They have also been
found in the spinal canal and in various other locations. Finally, about
January they appear beneath the skin of the back, forming the well-known
swellings. The posterior end of the grub is near the small opening in the
hide, through which the grub breathes and discharges its excrement, and
through which