Had any one of our indigenous flies similar poisonous qualities we should never have been able to escape from barbarism; if, by any fatal chance, the tsetsè were to settle among us, our prosperity would soon be at an end, and our civilisation imperilled! Reflections such as these are well calculated to humble our pride and check our presumption! The Abyssinian Tsalt-salya or Zimb, described by Bruce, seems identical with the tsetsè, or produces at least similar symptoms. At the season when this plague makes its appearance, all the inhabitants along the sea-coast, from Melinde to Cape Gardafui, and to the south of the Red Sea, are obliged to retire with their cattle to the sandy plains to preserve them from destruction. The French traveller, D’Escayrac, tells us of a fly in Soudan which leaves the ox uninjured but destroys the dromedary. On account of this plague the camel is confined to the northern boundary of the Soudan, while the oxen graze in safety throughout the whole country. This fly has caused more migrations among the Arabs of the Soudan than all their wars; and in the dry season it even drives the elephant from Lake Tsad by flying into its ears. [Illustration: LOCUST.] Though the locusts not seldom extend their ravages to the steppes of southern Russia, though they have been known to burst like a cloud of desolation over Transylvania and Hungary, and stray stragglers now and then even find their way to England, yet their chief habitat and birthplace is the torrid zone. They wander forth in countless multitudes, and at very irregular periods; but how it comes that they are multiplied to such an excess in particular years and not in others, has never yet been ascertained, and perhaps never will be. They are armed with two pairs of strong mandibles; their stomach is of extraordinary capacity and power; they make prodigious leaps by means of their muscular and long hind legs; and their wings even carry them far across the sea. On viewing a single locust, one can hardly conceive how they can cause such devastation, but the wonder ceases on hearing of their numbers. Mahomet--so say his followers--once read upon the wing of a locust: ‘We are the army of God; we lay ninety-nine eggs; and if we laid a hundred, we should devour the whole earth and all that grows upon its surface.’ ‘O Allah!’ exclaimed the terrified prophet, ‘Thou who listenest patiently to the prayers of Thy Servant, destroy their young, kill their chieftains, and stop their mouths, to save the Moslems’ food from their teeth!’ Scarce had he spoken when the angel Gabriel appeared, saying, ‘God grants thee part of thy wishes.’ And, indeed, as all true believers know, this prayer of their prophet, written on a piece of paper, and enclosed in a reed which is stuck in the ground, is sure to preserve a field or an orchard from locust devastation.