grass (fig. 21), or fall into drinking water, and
finally may be swallowed by cattle. Stiles writes as follows:

Flukes may produce a serious, often fatal, disease, more especially in
younger animals. The symptoms are somewhat similar to those produced by
worms in the stomach. The first symptoms are generally overlooked, the
disease not attracting attention until the appetite is diminished;
rumination becomes irregular, the animals become hidebound, and the coat
dull and staring. The staring coat is due to the contraction of the
muscles of the hair follicles. The visible mucous membranes become pale,
eyes become dull, there is running at the eyes, and the animal gradually
becomes emaciated. As the disease advances the milk supply is lessened,
fever appears, there is generally great thirst, but the appetite almost
ceases; edematous swellings appear on the belly, breast, etc.; diarrhea
at first alternates with constipation, but finally becomes continuous.
The disease lasts from two to five months, when the most extreme cases
succumb.

Most of the German cattle are said to be infested with liver flukes, but
even when a large number are present the nourishment of the cattle is
not disturbed. Thickening of the gall ducts, so that a so-called
"Medusa's head" forms on the surface of the liver toward the stomach,
appears in even well-nourished animals; even in cases of a cirrhosis of
the liver it is seldom that any effect upon the cattle's health can be
noticed, and so long as a portion of the liver tissue about twice the
size of the fist remains intact, the nourishment of the animal may be
comparatively good. It is rare that one sees a generalized edema in
slaughtered cattle as a result of fluke invasion, and even in the
heaviest infections of young cattle only emaciation is noticed.

_Treatment._--Medicinal treatment is unsatisfactory. The disease may be
prevented to a considerable extent by giving animals plenty of salt,
and by introducing carp, frogs, and toads into infected districts;
these animals destroy the young stages of the parasite and feed upon
the snails which serve as intermediate hosts.

The drainage of wet pastures and the avoidance of swampy lands for grazing
purposes are important measures in the prevention of fluke diseases.

Railliet and others have recently recommended the application of lime to
fluky pastures, having discovered that very weak