rm of microorganism the
contagious character of which is poorly developed. This accounts for the
slow transmissibility of the disease from one animal to another. In fact,
malignant catarrh is a type of that class of affections scientifically
known as miasmatic diseases; that is, they remain stationary in stables
with damp floors, low ceilings, poor ventilation, and bad sanitary
conditions in general. Such places furnish a favorable seat of propagation
for the infective material, and it will remain active for a long time,
causing the loss of a few animals each year. One European veterinarian
reports an instance in which the disease remained for 25 years on the same
farm, attacking in all 225 animals, with a mortality of about 98 per cent.

The disease is most common in late winter and early spring, at all
altitudes, and has a special preference for young, well-nourished cattle,
although older animals are not immune. The time between the entrance of the
infective principle into the body of the animal and the appearance of the
first symptoms is relatively very long, averaging, according to German
investigators, from 20 to 30 days. Fortunately, it is not a disease which
spreads to any great extent or which causes severe losses, and hence
legislative enactments do not seem to be necessary for its restriction.

_Symptoms._--These are extremely variable according to the point of
localization of the lesions. It is usually ushered in with a chill,
followed by a marked rise of temperature (104 deg. to 107 deg. F.). The head
droops, the skin is hot and dry, and the coat staring. Quivering of the
muscles in various parts of the body is frequently observed. Marked
dullness of the animal, passing, according to some observers, into an
almost stupefied condition later on, is quite common. The secretion of milk
stops in the beginning of the disease, and loss of flesh, invariably
associated with the disease, is extremely marked and rapid. The lesions of
the eyes may best be likened to moon blindness (periodic ophthalmia) in
horses.

There is first an abundant secretion of tears, which run down the face. The
lids are swollen and inflamed, and indeed this may be so marked as to cause
involuntary eversion, exposing the reddened conjunctiva to view. Sunlight
is painful, as is shown by the fact that the animal keeps the eyes
continuously closed. This inflammation may extend to the cornea, causing it
to assume a slightly clouded appearance in