15 
(3) it is usual to find the same organism in the water- 
supplies at the time. 
TABLE II(d). 
Table showing the perceniage frequency of various organisms in 
Madras water-supplies in three quarters, 1908-09. 

RIVER. LAKES AND RESERVOIRS. 

Quarter | Quarter | Quarter } Quarter | Quarter | Quarter 
Organism. ending | ending | ending | ending | ending | ending 
30-9-08. [3 1-12-08.| 1-3-09. | 30-9-08. |31-12-08.| 1-3-09, 



— — | coe eared TP 
°G % % % % % 
B. coli communis 4°2 8°75 | I a 31 Nil 
} | 
Lactis xrogenes Si 5°O | a5 3°7..|.5 268 12°3 
Coscoroba a es | 5°O | 19 5°8 | 15"O 13°] 
Cloace alee 50°C | 8°75 | 5 43°8 13°1 | aa 

In support of this latter statement we wish to draw 
attention to Table II (d) where it will be observed for the 
quarter July, August and September, bacillus cloace was 
fairly common in river water, very common in lakes. Analy- 
sis of human feces and cowdung during the months of July 
and August also shows a marked prevalence of this organism. 
Similarly in the second quarter, in all the water-supplies, 
there was a great falling-off in the number of cloaca, accom- 
panied by a decline in its numbers in cowdung and feces. 
Another striking example is the rapid increase in the preva- 
lence of coscoroba in both human feces, cowdung and 
the water samples contemporaneously—vide Tables II (c) 
and (d). 
The third and perhaps the most important example is 
furnished by October 1908. At this period by accident it 
was discovered that in feces of several animals and in a large 
number of the water-supplies some rare organisms were 
observed to be quite common. Table II (e) shows the results 
