29 
the water and looked like a bright green lawn. It was growing in 
from 4 to 8 feet of water; but the water was not visible. Fish were 
around the edge and some in the mass of leaves, but not many, for 
they evidently could not penetrate the growth. The breeding of 
Anopheles would be called only moderate, but that of others was 
very profuse. Anopheles were most abundant where the leaves were 
not very thick. The others were everywhere. The Anopheles de¬ 
veloped were A. quadrimaculatiLS. Owing to an accident all the 
pupae captured, except the Anopheles, died. Later Dr. Howard 
reported specimens sent him as ZJranotaenia Sapphirinas and Culex 
of undetermined species. 1 * Since this pond was only 14 months old, 
evidently this grass is of very rapid growth. I have seen it in one 
other pond, a lake at Columbus, Ga.^ Avhere it covered the whole sur¬ 
face of the lake—some 6 to 8 acres. It is then capable of doing an 
immense amount of harm in increasing the propagation of mos¬ 
quitoes. Two tufts were seen lower down in the same pond and one 
had been seen near Dawkins—some 8 miles above on the other side 
of the river. This plant was identified by Dr. Hitchcock, of the 
Bureau of Plant Industry, as Hydrochloa carolinensis. It is known 
locally as Silver Leaf, but is rare. Only one person in the neigh¬ 
borhood was encountered who had ever seen it. He said that it had 
destroyed a fishpond. It encourages profuse breeding of mosquitoes. 
We had this patch raked out and the other three as well, with 
directions to visit the place once every two weeks and rake out every¬ 
thing that appeared. The three small ones could be destroyed by 
one operation—the large one could not. This is given in detail, be¬ 
cause (1) it is the first time a particular aquatic growth has been 
a serious problem and (2) this was an exceedingly serious one, and 
if this grass were to spread as it had begun, an insoluble one. In 
some older ponds, as we shall see, aquatic vegetation may be quite a 
problem, but we have seen none so bad as this. 
HAMMOCKS IN PONDS. 
We found nothing of sanitary importance between the bights 
above the mouth of Cannon’s Creek and the dam. To our surprise 
we found no breeding of sanitary importance even at Parr Shoals 
on hammocks and floating islands. True, they had been set adrift 
before our arrival, but a number of them had not gone far, or 
others had formed. Some of them were breeding moderately, but 
nine out of ten were barren. At Stevens Creek we found very 
scant} 7 production, generally none on the larger hammocks. Where 
new floatage had lodged against them, it contained larvae—sometimes 
1 For the identification of this last it was necessary to have the larvae, and as we had 
gone to Alabama before we received his letter we were unable to furnish them. 
