18 
nearly all of the first 20 miles, coimting from the dam. the pool lies 
against high bluffs with steep banks, frequently of sheer rock. Only 
where ravines and water courses enter are the banks at all sloping. 
Even the mouths of large creeks give no perceptible width to the 
pool. The creeks themselves run in gorges. About the fork, how¬ 
ever. there is considerable level land overflowed in a broad area at 
the mouth of Prescott Creek. The bayous of the creeks above the 
fork, as high as Frog- Ague Creek at Cordova, are frequently broad 
and cover considerable area. 
Xaturally in a pool of the character of this one below the fork, 
there would be little accumulation of drift, except that which came 
out of a creek and stopped about its mouth. This was what was 
found. There was, however, a great deal of “ leaf floatage.” Many 
of the partly submerged trees were dying, and they dropped their 
leaves in the water. These gathered in the heads of bayous of 
creeks and in some bights. There was also about the heads of some 
bayous a lot of fine floatage, which apparently had been washed 
down the creeks and floated up from the flooded ground. There was 
much more floatage of the above kinds than on the Coosa, but far 
less of heavy drift. There was such drift, however, in Prescott 
Creek Bayou and in some of the bayous near Cordova. 
Biological condition .—The biological condition of that part of the 
pool next to the dam differed from that found at the Coosa pool. 
Quite frequently we found complete breeding places for anopheles 
in the pond about the heads of bayous of branches. 1 Anopheles 
larvae were found in leaf floatage, especially among the small leaves 
of the beech and pine needles, but also in the fine floatage collecting 
at the heads of some bayous. In some places they were breeding 
profusely, more so than had been found in an}’ pondwater on the 
Coosa. Where there was little floatage there were no larvae, although 
the converse was not true. The majority of such bayous and bights 
showed no breeding, or very little. The same was the case along 
the open bank of the pool. The affluent streams were not breeding 
heavily in live water. There were two exceptions to this : Big Indian 
Creek, below the dam, and the headwaters at Hollman's branch, 
entering above the dam. 
Of the 100 larvae developed here all were A. punctipennis , except 
four A. quadrimaculotus. Small fish were very abundant in some 
places; in many others entirely absent. Apparently they had not had 
time since the filling of the pool to spread all over it. Indeed, the 
rarity of shallows, etc., make it a pool not very well fitted for 
minnows, and the total number seen was not large. 
1 By a complete breeding place is meant a place in which the imago develops from the 
egg deposited at that place. 
