6 
unusual features and that a biological survey of them was immedi¬ 
ately advisable to determine the existing conditions, 1 and especially 
to enable us to give advice to correct certain insanitary conditions 
which it seemed very probable would obtain about portions of them. 
The survey of the area to be covered, but not yet covered, by the 
impounded water contemplated under (1) was therefore postponed 
and that of these two ponds taken in its place. This was the more 
advisable, as, owing to industrial conditions, the site selected for 
this survey would not be covered by water for at least two years. 
SURVEY OF PONDS IN ALABAMA. 
In order to examine the pond under different conditions of season, 
water, etc., 2 two surveys of the pool of Lock No. 12, Coosa River, 
were made, May 28 to June 25 and August 18 to September 19. The 
power plant and Talladega Springs were used as bases to work from 
in both surveys and a power launch was used to reach the different 
parts of the pool. The actual work was done on foot or in a canoe. 
This pond was in its second season, having been filled in June or 
July,* 1914. It had been the object of quite a thorough survey by 
Le Prince and Donley during October and November, 1914. In our 
June, 1915, survey it was examined by u sampling.” All creeks and 
large branches were examined up to and beyond backwater, and por¬ 
tions of the banks of the main pond and of the bayous caused by 
these affluents were selected in different places and examined thor¬ 
oughly. Large numbers of sample banks were examined and pains 
taken to select those that would be apt to breed or shelter Anopheles 
larvte. Some places were examined more than once at intervals of 
from four days to a week. 
In the survey made in August and September a few localities 
believed to be fairly typical were examined carefully, and more than 
once. The survey was an intensive study of such type places, and 
no attempt was made to examine a great number of places, much 
less the whole pool, which has a shore line estimated at from 90 to 
120 miles. Some examination was also made of territory beyond 
the influence of the pool. This work was fairly complete, and the 
state of the pool, as affecting malaria incidence for this year, can 
be given with a fair degree of accuracy. 
The survey of the pool of Lock IT on the Black Warrior was not 
attempted on the same scale as was that of the Coosa pool. It would 
have required the entire summer to do so, and the information gained 
would have been less than that which the same time spent elsewhere 
would give. We spent from June 27 to July 17 on this pool and 
1 They were filled in June or July of last year. 
2 See Reprint No. 244 from Public Health Reports, p. 12. 
