CULlOlM. 
567 
species, and are often furnished with small floats to keep them at the 
surface. Several lots of eggs may be laid by the same female. The 
larvse emerge from the under side of the eggs and thus go directly into the 
water. They have a very distinct head and thorax, the head usually 
bearing eyes. The jaws are provided with a thick fringe of hairs, and 
their continual motion sweeps towards the mouth the little particles of 
vegetable or animal matter on which the larvse feed. Some species are 
cannibals : these have specially modified jaws to fit the habit, and will 
often attack and consume Chironomid larvae considerably larger than 
themselves. The abdomen is composed of nine segments ; the eighth 
bears gill-processes and the ninth is prolonged upwards in Culicines into 
a 4 4 siphon ’ ’ or breathing-tube, at whose summit the two big longitu¬ 
dinal tracheae open. The end of the tube is surrounded by a fringe of 
fine hairs, and when these are expanded on the surface of the water, they 
prevent the tube from sinking and the opening of the tracheae from being 
submerged. The Culicine larva spends a considerable part of its life 
thus suspended by its siphon-fringe to the surface-film of the water, but 
if it is frightened or wishes to feed at the bottom, it can shut up the fringe 
like an inverted umbrella, and its own weight then causes it to sink. It 
can swim rapidly with a quick wriggling motion, the many hairs and 
bristles about the tail acting as a kind of fin. 
The larvae are of two types, those of the Culicine type just described 
being easily distinguished from Anopheline 
larvae by their characteristic attitude when 
resting, as is also the case with the adult 
mosquitos of these two groups. The Culicine 
larva is supported in the water only by the 
siphon-fringe, while its head and body hang 
down ; the siphon of the Anopheline larva 
is extremely short, and it possesses in addi¬ 
tion a series of branched or tufted hairs 
( 4 4 stellate hairs”) along the body. The 
hairs are shaped rather like little palm-trees, 
and their branches resting on the surface- 
film of the water support the larva whose 
Fig. 365— Position of culicine body in consequence does not hang down, 
[After Giles) x 5. but lies along horizontally ]ust below tile 
