412 MOSQUITOES OF NORTH AMERICA 
success. In his travels through southern Oran (Algeria) in 1892, Mr. Vosseler 
found a widely distributed species occurring in thousands, not only in the springs 
of salt or magnesia water in the oases and in the irrigation ditches, but also 
in the highly polluted, badly smelling pools used to water camels, and in which 
300 to 400 camels often waded in one day. He found the same species after- 
ward in pure, fresh water, in hot springs, and in brackish water. He also found 
that it inhabits the subterraneous waters of the desert and is probably brought 
up by the boring of artesian wells. One of the officers of the garrison situated 
in the midst of a salt basin without outlet pointed out to Mr. Vosseler that this 
little fish eats mosquito larve, which explained the comparative absence of 
mosquitoes in that locality. Mr. Vosseler attempted the introduction of these 
fish into Germany and succeeded very well, in spite of inadequate preparation. 
They began to lay eggs within a week of their arrival and became accustomed 
to any animal food. They always prefer mosquito larve and small crustaceans. 
The fish in question is Cyprinodon calaritanus. The female is 8 cm. long and the 
male 5 cm. The eggs are attached singly to water plants or stones at the rate 
of one or two a day. Mr. Vosseler states that the excellent qualifications of the 
species are shared by other members of the same family, and in German East 
Africa at least two genera and five species are known to occur. 
MR. THIBAULT’S OBSERVATIONS. 
In considering the normal relation between mosquitoes and fish, Mr. James 
K. Thibault, Jr., Scott, Arkansas, in a recent communication presents his views 
and gives an interesting instance of mosquitoes breeding in the presence of fish, 
which he considers typical of conditions in some localities : 
“ Personally I do not think that mosquitoes ever breed in the presence of fish 
if the water is open, allowing the fish free access to the larve, yet it is a matter 
of common observation that under certain favorable circumstances some species 
do breed regularly in streams where fish are abundant. Yet even where con- 
ditions are favorable only a very few species seem to take advantage of it. So 
far as my own observations go the only mosquitoes that regularly do so in this 
locality are Anopheles quadrimaculatus and Culex abominator. 
“ Conditions are favorable where the surface of the water becomes carpeted 
with aquatic vegetation, which restrains the fish in their movements, yet allows 
ample room and protection for the larve of the above-named species. There is 
a certain deep, slowly running bayou here that is the main breeding place for 
quadrimaculatus and abominator at present while two years ago not a larva 
could be found there at all. The explanation is simple and may be given as a 
typical example of its kind. Two years ago launches passed through this bayou 
daily, and all logs and drift were removed as soon as found, so that the water had 
free passage and the pond weeds found no foothold, except very near the banks 
where they were completely destroyed by stock. After the launches stopped pass- 
ing through this bayou, logs soon accumulated and the pond weeds immediately 
took possession, so that throughout the present season quadrimaculatus and 
abominator have bred continuously and abundantly in this bayou. 
“ It must be noted in passing that the larve, pupex, and freshly emerged adults 
bred in such a location are invariably bright grassy green in color, which gives 
them additional advantage of the fishes. This is not the case with larvae, 
etc., found in other places.” 
