THE INSECT WORLD. 3 
holes in the soil or in old walls, and building cells, or rushing from 
flower to flower gathering honey, collecting pollen, and not in a 
temper to be disturbed at their business, for they are putting by for 
the rainy day, and thinking of the store they must lay up with 
their eggs. A caterpillar is in great distress, and is traversing the 
sunshine in the strong grip of a gaily-coloured Sphex, which is 
about to place it in the nest, where its young will make a meal 
of it some day or other; and an Ichneumon fly, with its slim 
waist and long, slender body, armed with a sharp ovipositor, is 
just about to attack another heavy feeder, and to lay an egg 
beneath its skin. Well armed and cuirassed carnivorous beetles 
and dragon-flies are busy slaying and eating the quiet munchers 
of leaves and the suckers of flowers; and the delicate water 
insects are revelling in a constant fight, or are gormandising on 
their weaker prey. 
Elsewhere there is a different scene of intense vitality. The 
blow-flies are hovering around, and are placing their eggs in the 
putrid dead body of a small animal, some beetles are burying 
portions of it, and soon a mass of maggots will revel in the rest. 
Most wonderful are the uses of insects. They fertilise the soil 
by scattering decomposing matters, and prevent them from vitiating 
the atmosphere. A plant grows luxuriantly and increases too 
rapidly ; the caterpillars arrest its growth and propagation; the 
caterpillars after a while become too destructive, and the Ichneu- 
mons kill them by myriads. The vegetarian insects which lead 
a luxurious and quiet life tend to increase greatly in number, 
and yet the carnivorous kinds are ever at hand to keep this 
prolific race within bounds. Century after century this curious 
equilibrium is maintained in Nature, and although occasionally 
locusts increase to such an extent as to ruin great districts, still, 
as a rule, the interference of man produces the ravages of the flies 
that injure his crops, for he constantly disarranges the balance 
of insect power. 
The crab tribe represents the insects in the seas, along the 
coasts, and in the rivers, and its members lead all sorts of lives 
under very diverse circumstances. 
It would appear that Nature requires the multiplication of the 
Articulata to be carried to the greatest excess, and that they 
B 2 
