22 
Numerical comparison is not possible here, as the houses undoubt¬ 
edly received mosquitoes from a number of breeding places, some 
producing one species and some the other. They were, however, on 
the average decidedly closer to places producing A. punctipennis 
than to those producing A. quadrimaculatus , and the production of 
the first was many times greater than that of the second. 1 The 
houses next to the Sulphur Creek Bayou are not included in this list. 
They gave much greater numbers of A. quadrimaculatus. 
Having regard to the production and proximity of source of pro¬ 
duction, the general fact that A. quadrimaculatus is much more often 
found in residences than A. punctipennis has been noted by our 
party for some time and, it is presumed, by others; but this is the 
first opportunity we have had for a comparison of this habit of the 
two species with even approximately definite numerical data. It 
is less extensive in number of houses (10) and less close in the ap¬ 
proximation of the production than one could wish. 2 It should be 
observed how much oftener A. punctipennis were found in out¬ 
houses than in residences. We have found this to be always true. In 
our experience A. punctipennis has been found only sparsely in 
residences in the daytime. Whether they do not enter at night, or 
enter at night and leave, is a question we hope to answer next year. 
On it depends whether they are a factor to be seriously reckoned with 
in the conveyance of malaria, and thus it is a matter of the greatest 
importance to the sanitarian. 
AQUATIC VEGETATION—SURVEY OF POND AT BAY VIEW. 
A survey was made of a small pond at Bay View near Birming¬ 
ham, furnishing water for the Tennessee Coal & Iron Co. This pond, 
the writers were informed, had not produced mosquitoes to an 
appreciable extent until the summer of 1915, and its environment 
had been free from malaria. It was several years old. There was 
no brush on its banks, and the banks had been cleaned with a hoe 
in the early summer. The company was anxious to have no malaria 
among its emploj^ees. This year, however, there was considerable 
malaria in the neighborhood of the pond. 
We found a singular condition of affairs. The pond was skirted 
by an aquatic plant, Naias flexibiles , 3 which lay in the water like 
kelp only far finer and more flexible and as thick as it could well 
grow. It was close up to the shore and apparently 4 had finished 
its growth and was dying and decomposing. Dipping from the 
1 Note, too, the reversed proportion at the walled spring. 
2 Very few observations made early last spring and in October may tend to show that 
A. punctipennis is more often found in residences in cold weather than in summer, but 
the observations were too few to be worth recording here. 
3 Hitchcock, Bureau of Plant "Industry. 
4 The survey was made on Sept. 22. 
