Natural Enemies of Mosquitoes. 73 
year I had reported that dense masses of gnats were seen 
along the Downs near Wye, appearing like columns of smoke in 
the valley, rising and falling. I did not see this, but visited 
the Down-sides the next day and found great numbers of male 
0. pijpiens about in the evening, dancing in little clouds where 
they were sheltered from the wind. 
Romolo Gessi Pascha, in his book “ Seven Years in the 
Soudan,” p. 4-7 (1892), speaks of “ myriads of mosquitoes which 
obscured the air ” at Meshra-el-Rek. If we go to the Arctic 
regions we get similar phenomena, for Dr. Lugger informs 
Professor Howard that Dr. Emile Bessels, of the Polaris 
Expedition, was obliged to interrupt his work in Davis Straits 
(latitude 72° N.) on account of the multitude of mosquitoes. 
TV hat these dense swarms mean I do not know. In those I 
have seen, and in the case recently reported, males were pre¬ 
dominating. It may be these masses of gnats are males gathered 
together to attract the females, who are known to fly to the 
males to be fertilized in the genus Culex. 
NATURAL ENEMIES OF MOSQUITOES. 
Nearly every insect has one or more natural enemies, but it is 
only now and then that they are of any great service in lessening 
the numbers of any particular pest. Natural enemies, never¬ 
theless, tend to keep the equilibrium of Nature, and to restore 
it when upset, although we may not see any great change in 
this respect; but destroy the natural enemies, then one will 
soon find out the important part they play in the economics 
of life. 
Mosquitoes, like all the rest of the insect world, have many 
such enemies, but few are of any real importance in connection 
with the destruction of these annoying insects. Among the 
most important enemies the mosquito has to fight against 
are fish; many kinds of fish devour with great avidity the 
“ wrigglers ” of Culex, hence we find but few of these aquatic 
larvae in water where fish exist. That they may be employed 
on a small scale with success to keep these pests in check may 
be gathered from the following quotation from one of Dr. St. 
George Gray’s letters : “A friend of mine living near Chausee 
keeps down the mosquitoes by having a couple of tubs of fish 
in his yard. He says he has no mosquitoes now. I lived 
