105 
that the greater rarity of typical coli communis in summer 
is due to the fact that coli communis*of Escherich rapidly 
disappears in summer weather. 
From a certain amount of work which has been carried 
out on polluted earth, coli communis has been found on one 
occasion to remain alive in ordinary damp ground for a 
period of 97 days. 
Oxytocus Perniciosus and Bacillus No. 08. 
These organisms have the most remarkable position in 
nature. It is not by any means certain that this is a true 
fecal organism, but there is no doubt that it is fairly fre- 
quently found in feces of man and animals at certain times 
of the year. In India, both in Madras, Bengal, and in the 
United Provinces, these organisms have been found in rivers, 
lakes and well waters at one time or another during heavy 
monsoon weather. They are nearly always found in water 
with every indication of very recent pollution. The samples 
obtained show that in about go per cent. the lactose fer- 
menters were present in ‘or of cubic centimetre ; the total 
colony counts are extremely high, usually about 2,000 or 3,000 
per c.c. ; in about 50 per cent. coli communis was also asso- 
ciated with oxytocus ; and in the few samples where glucose 
and lactose broth have both been used, the acid and gas 
line is practically identical in the two media. Consequently, 
there is every reason for supposing that this little group of 
organisms is usually found in connection with dangerous and 
recent pollution. Very occasionally in a comparatively good 
water one of these organisms is isolated. This occurred 
once or twice in certain rivers in Madras. In our work on the 
Red Hills Lake in Madras in rg09 in Chapter VIII it was shown 
clearly that this organism disappears with very great rapidity. 
It is never found in dry and hot weather, either in the feces 
of man or animals, or in water-supplies. A careful and ex- 
haustive search was made, using inulin broth, in order to try 
to isolate this bacillus ; on every occasion this proved unsuc- 
cessful, except during the monsoon weather when in some 
years 1t was quite common. The great rarity of these organ- 
