ting the flesh of diseased animals which has not been
thoroughly cooked. These forms of the disease are more fatal than those in
which the disease starts from the skin.

BLACKLEG.

[Pl. XLII.]

Blackleg, black quarter, quarter ill, symptomatic anthrax, charbon
symptomatique of the French, Rauschbrand of the Germans, is a rapidly
fatal, infectious disease of young cattle, associated with external
swellings which emit a crackling sound when handled. This disease was
formerly regarded identical with anthrax, but investigations by various
scientists in recent times have definitely proved the entire dissimilarity
of the two affections, both from a clinical and a causal standpoint. The
disease is produced by a specific bacillus, readily distinguishable from
that causing anthrax. (Pl. XXVIII, fig. 4.) Cattle between 6 months and 2
years of age are the most susceptible. Sucking calves under 6 months are
rarely attacked, nor are they so susceptible to inoculation as older
animals. Cattle more than 2 years of age may become affected, but such
cases are infrequent. Sheep and goats may also contract the disease, but
man, horses, hogs, dogs, cats, and fowls appear to be immune.

Like anthrax, blackleg is more or less restricted to definite localities.
There are certain pastures upon which the disease regularly appears in the
summer and fall of the year. As to any peculiarities of the soil nothing is
definitely known. Some authors are inclined to regard moist, undrained, and
swampy pastures favorable to this disease, but these theories will hardly
hold, as it is found in all kinds of soil, in all altitudes, at all seasons
of the year, and under various climatic conditions. It occurs in this
country from the Atlantic to the Pacific and from Mexico to Canada, but it
is more prevalent in the Western and Southwestern States. In Europe it
exists in France, various parts of Germany, in Belgium, Norway, Denmark,
Italy, and in the Alps of Switzerland. In Africa it occurs in Algeria and
to some extent in Natal and bordering countries. In South America it
prevails quite extensively throughout Argentina. Cattle in Cuba and
Australia also suffer.

_Cause._--The cause of the disease is a bacillus resembling in some minor
respects the anthrax bacillus and differing but little from it in size. It
also possesses the power of forming within itself a spore. In Plate XXVIII,
figure 4, this is represented as an uncolored spot located in one end of