102 THE INSECT WORLD. 
white, and of elongated shape, which it deposits on the stems and 
leaves of aquatic plants. ‘The eggs are hatched at the beginning 
of spring, or in May, and the young ones at once begin to swim 
about like their mother, on their backs, belly upwards. M. Léon 
Dufour says on. this subject :— 
‘A dorsal region, raised like a donkey’s back, or like the rounded 
keel of a boat, and covered with a velvety substance, which renders 
it impermeable, numerous fine fringes which garnish either the 
hind legs, or the borders of the abdomen and thorax, or lastly in 
a double row a small crest or comb running down the surface of 
the belly, and which spread themselves out or fold themselves 
in at the will of the insect, just like fins, favour both this supine 
attitude and the accuracy of the swimming movements of the 
Notonecte. Since nature, which seems often to delight in pro- 
ducing extraordinary exceptions to her ordinary rules, thus bearing 
witness to the immensity of her resources, had condemned this 
animal to pass its life in an inverted position, it was necessary, for 
the maintenance of its existence, that it should provide it with an 
organisation in harmony with this attitude.. It is also for this 
object that its head is bent over its chest ; that its eyes, of an oval 
shape, can see below from above; that the front as well as the 
middle legs, agile and curved, solely destined for prehension, can 
to a certain extent become unbent by means of the elongated 
haunches which fix them to the body, and clutch firm hold of 
their prey with the strong claws which terminate the tarsi.” 
HoMoPTERA. 
We come now to the second group of the order Hemiptera, 
namely, Homoptera. 
The insects which compose this division are numerous. They 
may be arranged into three great families, of the most remarkable 
members of which we shall give some account. These are the 
Cicadide, the Aphide, or Plant Lice, and the Coce:de. 
The Cicada is the type of the first of these families. It has a 
deafening and monotonous song; as Bilboquet says, in the ‘ Sal- 
timbanques,” “those who like that note have enough of it for 
their money.” Virgil pronounced a just criticism on the song of 
