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bristles is found on the ventral side. The seventh segment is 
somewhat more luxuriously equipped; the bristles radiate almost 
coronary into all directions (fig. 2). 
The Mansonia-larva is a more hairy animal than our Culex- 
" larvæ. The importance of these hairs cannot be- understood from 
a mere dorsal view of the larva: (fig. 1). ;The- hair-cover of the 
animals, especially with regard to the aquatic ones, always ought 
to bee studied upon living specimens and in their natural attitu- 
des. Thus we will regard fig. 2, reproduced after a drawing made 
from a living specimen examined under the above-mentioned bino- 
cular microcope. In my aquaria I have almost always found the 
animals in the attitude presented in the figure. It will be seen, 
that the many different hairs of the body point almost towards 
every direction. Every motion of the water, everything that hap- 
pens in the surroundings, will be brougth to the knowledge of the 
animal before it reaches the body itself. On account of their 
great length the antennæ master a relatively considerable body of 
water in a forward and downward direction. The two long brist- 
les on the epistome protrude forwards. The hairs of the dorsal side 
of the head are directed obliquely forward and upward, and the 
large bundles of bristles on the thorax extend partly over the head, 
partly along the sides of the same. The bundles of bristles on 
the dorsum play a part as supporting hairs, but besides they serve 
as indicators af movements of the body of water between the ani- 
mal and the stem of the plant; those on the ventral side have 
a similar function with regard to the water beneeth the animal. 
The large swimming-brush extends backwards far beyond the hind 
end of the body; the four large bristles arising from the &8th seg- 
ment get information of everything that happens above the animal. 
Without bristles the animal would only be able to get information 
relating to variations within a very small area of the surrounding 
medium. Other animals, enemies etc. are not able to force their 
way unobserved into the very body of the wriggler. If we try to 
approach a needle within a distance of some millimeters from the 
animal, we will immediately understand this; instantaneously the 
wriggler will make some very conspicuous curvations of the body, 
but usually it will not let go the hold of the plant. It is like åa 
man-of-war with its torpedonets folded out. Probably the very 
small eyes have but a slight importance as sensitive organs. Liv- 
