47 
Habits and Food, of Larvae. 
Later on they swallowed, amongst other things, particles of 
sand, the green slime off stones, and frequently even picking up 
quite a large sand pebble and then dropping it again. 
Dr. Nuttall mentions the following plants found where 
Anopheles occur in England and Germany : TJlva, Spirogyra , 
Lemma, and various algae. They are also “ found in accumulations 
of aquatic plants torn up from the bottom of rivers and accumu¬ 
lated in little bays and inlets along the banks of the stream.”— 
(Daniels). They have been pointed out by various correspon¬ 
dents to be frequently found in company with Culex larvae. 
Clllex larvae. — Culex larvae behave in a very different 
manner, as well as being very different in structure, having a 
long respiratory siphon. Instead of lying horizontally at the 
surface they hang down vertically or slightly obliquely when 
at rest, the tip of the respiratory siphon being level with 
the surface film and the head hanging downwards. Directly 
they are in the least disturbed the larvae of Culex sink to the 
bottom, but soon arise by a slow upward movement, due to the 
buoyancy of their air-tubes, or by a series of sharper jerks. 
They will not remain below water for any length of time, but 
rise up as soon as they fancy the danger has past. Unlike 
Anopheles, they are very active, and can at once be told by 
these habits alone in the majority of instances; but Captain 
James, writing on the Filaria-carrying mosquito ((7. fatigans, 
Wied.), tells us that the larvae, like the Anopheles, move at the 
surface of the water by horizontal jerks, but in shape and every 
other respect they are so unlike that there is no danger of con¬ 
fusing them with each other. 
As far as my observations go on Cu 1 expipiens and C. nigrilulus, 
I have always noted that the young larvae lie almost at right 
angles to the surface for the first day or so of their existence. 
These so-called “ wrigglers ” soon grow, and become more and 
more active, darting about in sharp jerks in a zigzag fashion, or 
moving rapidly to the floor of the receptacle they are in. When 
resting the vibratile mouth parts are kept in constant movement; 
feeding, in fact, is incessant, breathing going on in an undisturbed 
way all the while through the siphon. The food swept into the 
mouth by the vibratile organs is very varied, consisting of algae 
and water Crustacea, such as Daphniae and Cyclops. I have bred 
C. nigritulus almost exclusively upon flagellate protozoa, which 
seems a very favourite food. Carnivorous habits also exist in 
