Dresden, but they were inclined to
attribute to the avian tubercle bacillus the cause of the peculiar lesions
of enteritis which they observed. In 1904 Markus reported this disease in
Holland, and subsequently it was observed in Belgium, Switzerland, Denmark,
and Great Britain.

_Cause._--The bacillus, which has been invariably demonstrated in the
intestinal lesions and mesenteric lymph glands in this disease, is a rod
about 2 to 3 microns long and 0.5 micron wide. It stains more or less
irregularly, like the tubercle bacillus, and moreover the similarity goes
further, in that the organism is also strongly acid-fast, which facts led
Johne and Frothingham to surmise that the disease was caused by avian
tubercle bacilli. However, it has now been plainly demonstrated that the
bacillus of chronic bacterial dysentery is readily distinguished from the
latter organisms, for while it resembles the tubercle bacillus in form and
staining qualities, no one has succeeded in growing it in culture media or
in reproducing the disease by injecting experiment animals.

_Symptoms._--Probably the first symptom noticed is that the animal is
losing condition despite the fact that its appetite is good and the food
nourishing. This is soon followed by a diarrhea which, while moderate at
first, soon becomes excessive and may be either irregular or persistent,
the feces being of the consistency of molasses and passed frequently. In
the meantime the hair becomes dry and harsh and the animal falls off
considerably in weight. The temperature, however, remains about normal. The
appetite does not seem to be greatly impaired until the last few weeks of
life, but nevertheless emaciation continues, the animal becomes more and
more anemic, great muscular weakness and exhaustion are manifested, and
death follows, apparently as the result of the persistent diarrhea and
great emaciation. The disease may continue for four or five weeks or may
last for a year, or even longer, before death intervenes.

_Lesions._--The lesions observed on post-mortem are remarkably slight and
are out of all proportion to the severity of the symptoms manifested. The
disease appears to start in the small intestines, especially in the lower
portion, where the lesions are usually the most marked, but it also
involves the large intestines, including the rectum. The mucous membrane
may alone be affected, although usually in the long-standing cases the
submucosa is also invaded and