THE INSECTS' ASSAULT 237 A tiny, semi-invisible object silently sweeps up on the breeze ; it is followed by others, who become multitudinous, filling the air over the river with a mysterious maze of swift-moving shades. Myriads of bats glide flutteringly upstream, as if impelled by a single unseen power, until darkness hides them.

Then come tiny specks of light swinging across the water, chasing sparks from the funnel as if to find unknown brethren, and mingling, separating, winding amongst each other in an interminable, dazing confusion. It is the fireflies' dance, seen at its best in the drear wastes of the Mountain Nile " sudd," where they are the only creatures that show joy in life.

The difficulties of writing are considerable, for the insect world is malicious, much occupied, and entirely selfish. Ants galore career over the table and explore the interior of one's shirt ; mosquitoes parade, and cause one to follow their movements with animated interest ; winged ants rush everywhere in great haste ; hard, armoured beetles dash unavailingly against the wire netting, and lie sprawling outside ; grasshoppers and crickets jump in every direction but the one they are facing ; and even a grass mantis has become excited and dashes hither and thither, differing from his South African brother by a greater length of wing and celerity of movement. The rest are too numerous and too impatient and restless to mention.