244          Anthrax Infection Through Dirty Stagnant Pools

curve (Fig. 1) during certain years, the cause of which is still unknown. It
is prevalent throughout the year causing heavy mortality from April to Sep-
tember and in the month of December (Fig. 2). In this connection, it would
be interesting to note that as an infection in the soil it is quite natural for
Anthrax to break out in an epizootic form during the grazing season which,
in most of the districts, begins from the latter half of June. The source of
infection during the months of April and May, when practically no grazing
is available, has, however, remained a mystery. It is not uncommon to
find stall-fed draught animals also succumbing to Anthrax during the summer
season and here again the source of infection was unknown.

[NLS note: a graphic appears here - see image of page]

Fig. 2—Anthrax in Cattle. Monthly average mortality. (11-years' average—
      1924-35).

During the summer season of 1936 when green grazing was not available,
a number of outbreaks of an undiagnosed disease was reported from the Ratna-
giri district. Investigation which was carried out at the actual scene of these
outbreaks revealed that the disease was Anthrax. The writer also detected
a bullock which in spite of being daily yoked to cart and fed on dry foodstuffs
had fallen a victim to this disease. A careful search for the source of infec-
tion was, thereupon, made with the results that stagnant pools formed in the
beds of nullahs and rivulets appeared to be the only probable source as there
was clear history that animals which had died of Anthrax were daily driven
to such pools for watering purposes. An examination of these stagnant pools
showed a thin layer of shiny brittle scum floating on the surface and dirty
brownish water containing putrefying vegetable matter. Samples of water
were collected from two pools, one at Lanja and another at Wilavade, and
5 c.c. of each sample were injected into a guinea-pig. The guinea-pig injected
with the water sample of Lanja died within three days and its heart blood gave
rise to a pure culture of B. anthracis on agar medium.