43 6 TRANSFORMATIONS OF INSECTS. 
Dugés saw the eight legs of the perfect insect forming beneath 
the transparent skin of the nymph, whose body was smooth, oval, 
and just like a little yellow egg. After a while a tiny brilliant 
red Trombidion came forth, small, but with eight legs, and it was 
a perfect spider with tracheee. These mites die if left for a short 
period in water, and they live by sucking the juices of the 
creatures upon which they are parasitic, such as-the spider just 
mentioned, the daddy-long-legs fly, and others. 
The Hydrachnide, or water ticks or mites, are spiders with 
trachee and unsegmented bodies that undergo metamorphosis, 
the larve being very unlike the perfect insect, and only having 
six legs. All the water ticks may be recognised by their hairy 
legs, so well adapted for swimming, and by the peculiar shape 
of their palpi, which enable them to cling on to plants and stones 
as if with anchors. These mites have a sort of plastron, which 
is formed by their flat, broad, and adherent haunches. 
The Harlequin, Afar histrionicus, lays its transparent eggs in 
layers, which look like so much gum, and the larvze which are 
hatched from them are aquatic. The larve have six legs, a 
flat almond-shaped body, with two large eyes, and the belly is 
reddish in colour, whilst the legs are blue. The adult has eight 
legs, and also numerous little points on the back, which secrete a 
viscous matter that forms into a web, in which the creature can 
live and breathe air whilst pursuing its usual life under water. 
The males of the genus Dzplodontus are very sociable, and so 
are the females; and little swarms of them may be noticed 
enjoying the warmth of the shallows. When thus disposed they 
often run great risks, for instead of watching the fall of the water 
on the mud, they allow it to take place suddenly, without their 
moving off, and then many a happy coterie is dried up and 
destroyed. The larve, like all the others, have six legs, and turn 
into immobile nymphs, which are watched with amusing polite- 
ness by the adult males. Wives appear to be at a premium 
amongst these spiders, and the males make up their minds about 
their future courtship before the nymphs are transformed ; hence 
the funny hugging and constant squeezing which are bestowed by 
the amorous eight-legged set upon the quiet and totally uncon- 
scious ladies zz futuro. When the egg-laying is going on the 
