s very common in cattle in the United States, at least 1 per
cent being infested. As a result considerable loss is entailed through
condemnations of beef carcasses by meat inspectors, because of the presence
of tapeworm cysts. All this loss could be avoided and the danger of
tapeworm infestation in human beings from this source could be removed by
the observance of proper precautions in disposing of human excreta. At the
same time much sickness and many deaths from diseases (hookworm, typhoid
fever, etc.) caused by soil pollution would be prevented, and farm life
would be rendered much safer than under the poor sanitary conditions which
are responsible for the high percentage of tapeworm cysts among cattle in
the United States.

THREAD WORMS IN THE ABDOMINAL CAVITY.

Thread worms (_Setaria labiato-papillosa_) 2 to 4 inches long are
frequently found in the abdominal cavity. They seem to cause little or no
trouble. The embryos produced by these worms enter the blood vessels.
According to Noe, they are spread from one animal to another by stable
flies (see p. 503), but this has not been definitely proved. The roundworms
found occasionally in the anterior chamber of the eye (see p. 531) are
perhaps immature forms of this species which have reached this location
during their migration.

LUNG WORMS.

Lung worms (_Dictyocaulus viviparus_, fig. 24) in cattle are thread-like
worms 2 to 4 inches long, found in the bronchial tubes and producing a
condition known as verminous bronchitis. The life history of the parasite
is not fully known, but infection is evidently derived through the medium
of pastures where infested cattle have grazed. In the later stages of the
disease the cattle cough, especially at night. Young cattle are more
seriously affected than old animals.

_Treatment for lung worms._--Various treatments have been advocated for
lung worms, including fumigating with different substances and injections
of remedies into the trachea by means of a large hypodermic syringe or by a
special spraying apparatus, but none have been very successful from a
practical standpoint. About all that can be done is to feed affected
animals well and protect them from exposure, removing them from the pasture
and keeping them in dry yards or stables maintained in a cleanly, sanitary
condition.

The methods of prevention in general are similar to those described under
the discussion of the twisted stomach worm (p. 521).

[Illustr