26 
more difference in the elevation of the pond of Stevens Creek than 
of the other, which also brought down a larger quantity of drift. 
Both ponds were closed in May or June of 1914, and both were 
surrounded hy a fairly level rich farming country, thickly settled. 
That of Stevens Creek was the better country of the two. The rise 
of water in each case was 35 feet. The length of Stevens Creek pond 
is about 8 or 9 miles, that of Parr 12 to 15. The banks of the 
original streams came out of the water in the first about 5 miles 
from the dam, and in the second about 6J miles from it, leaving 
rather large flats behind them covered with shallow water, especially 
at Parr. 
The work recommended after the February survey for the pond 
at Parr contemplated cutting the brush from the banks from high- 
water line to as low a line as possible, raking the drift and floatage 
up from the water’s edge; breaking up and setting adrift the ham¬ 
mocks and floating islands lodged in the woods; and some other 
minor work. An attempt to regulate the level of the pond so as to 
vary it from time to time and especially to keep it high in the 
winter was urged. The recommendations for Stevens Creek were 
somewhat different, but as they were not carried out/need not be 
mentioned. The recommendations at Parr were quite well carried 
out. The whole of the bank and edges were gone over, the brush 
was cut out, and the edges were raked. The side pools that needed 
it were ditched, giving fish access to them. A certain amount of this 
work was unnecessary, as it was done at places too far from resi¬ 
dences to be needed and at places where breeding would not have 
occurred anyway, and the same amount of work would have been 
better applied if certain dangerous places needing it had been gone 
over more often or more thoroughly. On the whole, however, this 
work was w T ell done and unquestionably lessened mosquito produc¬ 
tion. Occasion was taken during the biological survey to go with 
the man who had this work in charge and to show him just what 
was needed. 
The surveys were made from July 17 to August 16. The physical 
surveys had been made in February, and the fact that we were 
familiar with the general lay of the problems saved some time on 
the biological survey. 
SHELTER FOR LARVAE AND BREEDING IN THE PONDS. 
Leaf floatage was very little of a problem at Parr. Only in two 
creeks, Cannons and Hellers, was it sheltering larvae of any sanitary 
importance. In another year it will be negligible. This is not so 
on Stevens Creek. On account of its narrowness, the trees on its 
banks, and its length, leaves will be abundant for years, and we found 
