17 
given in that particular year and the following points should 
be observed :— 
(1) That the presence of these organisms is apparently 
contemporaneous with very heavy rain or monsoon conditions. 
(2) That the places where samples are taken are far apart ; 
in other words, the prevalence of the organism is observed 
over very wide areas. 
(3) That they all disappear with great rapidity from both 
faeces or water-supplies. Since the year 1908 we have care- 
fully looked out for these rare organisms, and we may point 
out that the same conditions have been observed in Madras, 
Bengal, and as far north as Allahabad, at exactly the same 
time of the year. The same group of organisms seemed to 
appear at certain times, always preceded by very heavy down- 
pours of rain, and they disappear when the heavy monsoon is 
over. 
In order to explain these parallel variations we have come 
face to face with the question—Is it the flora of the feces 
which determines the organisms in the water, or is the reverse 
true? And have the organisms present in the water any 
influence on the contents of the feces? There can be little 
doubt that under some circumstances the first of these questions 
may be answered in the affirmative. Although we are at 
present entirely ignorant of the cause of the appearance of the 
rare organisms in the discharges of man and animals in the month 
of October, there can be no reasonable doubt that the monsoon 
conditions, existing at the time, washed them into the water- 
supplies. This may also explain the coscoroba prevalence 
in December, January and February, for rains had been more 
or less common in November, December and the first week 
in January. But it certainly cannot explain the relation 
between the prevalence of cloacee in both water and faeces in 
August ; for first, during the months of July and August, 
there was practically no rain; and, secondly, we know what 
natural influences caused cloace to be so numerous in the 
water at this time, viz., that the organism is one of the last 
to survive in a stored water. 
Therefore, as it is certain that the faeces did not directly 
contaminate the various water-supplies at this time, it is all 
2 
