Mrs. Barber adds that " Voetgangers " have been known to attempt the passage of the Orange River when it was several hundred yards in breadth, pouring their vast swarms into the flooded stream regardless of the consequences, until they became heaped up upon each other in large bodies. As the livino- mass in the water accumulated, some pieces of it were swept away by the strong current from the bank to which they were clinging, and as the individuals tightly grasped each other and held together, they became floating islands, the locusts continually hopping and creeping over each other as they drifted away. Whether any of the locust-islands chanced to reach the opposite bank is unknown; probably some of them were drifted on land again.

They are by no means rapid swimmers; but do not easily drown, their habit of continually changing places and hopping and creeping round and round upon each other being most advantageous as a means of preservation. It is a common practice for these young locusts to form a bridge over a moderately broad stream by plunging indiscriminately into it and holding on to each other, grappling like drowning men at sticks or straws, or, indeed, anything that comes within their reach, that will assist in floating them; meanwhile those from behind are eagerly pushing forward over the bodies of those that are already in the stream and hurry-ing on to the front, until at length by this process the opposite bank of the river is reached; so that a floating mass of living locusts is stretched across the stream, forming a bridge over which the whole swarm passes. In this ingenious fashion few, comparatively speaking, are drowned, because the same individuals do not remain in the stream during the whole of the time occupied by the swarm in crossing, the insects continually changing places with each other; those that are beneath are striving to reach the surface by climbing over others, whilst those above them are, in their turn, being forced below. Locusts are exceedingly tenacious of life, remaining under water for a length of time without injury. An apparently drowned locust will revive if exposed to the warm rays of the sun, should it by chance reach the bank or be cast ashore.

As a rule, the individuals who first acquire wings do not leave the general swarm, but remain with it until they all are mature, when the whole body will take wing together. In cases, however, where great swarms of different ages are mixed, the adults will suddenly arise and be off, northward, leaving their companions, the " Voetgangers," to trudge along behind until such time as they can follow. By the middle of summer usually, the young have their wings, when they invariably all take flight and speedily disappear, travelling north, not a single specimen remaining behind in the Colony.

Distance to luJiich Szuar?ns may Migrate.

In the Old World the migratory locust is known to travel a distance of four hundred or five hundred miles into Central Europe from its permanent breeding-area in Asia; in North America the distance to which swarms may migrate in the course of a season may extend over a thousand miles.

The space over which a single flight may extend is not definitely known, but that it is considerable is certain. As the locusts rely chiefly upon the wind to bear them along, it depends upon the rate at which the wind moves, and the length of time they can remain in the air

without descending. That as a rule swarms under favourable conditions arise in the morning, about eight to ten o'clock, after the dew is off, and the warmth of the sun is felt, and settle down again to eat as night approaches, by four or five in the afternoon, is well established; that is, they can sustain themselves an entire day in the air. The rate at which they travel is variously estimated at from three to fifteen or twenty miles per hour, determined by the velocity of the wind; a day's tiight may therefore be estimated at from twenty to a hundred and fifty miles. But there are numerous facts which go to prove that a single flight may extend much farther than the longer distance here given: many persons believe the insects can remain in the air for days without coming down. While this is an extreme opinion, it seems undoubtedly true that they do sometimes continue their flights for more than a day; that they may, and do travel at night, has been recently clearly shown. Their general habit of alighting in the evening and resuming their journey next clay after sunrise, if the weather is fine, together with the difficulty of observing them at night, have led to the general, but erroneous, impression that there are no exceptions to the rule. There are good reasons for believing that the exceptions are much more numerous than might be supposed, that it is no uncommon thing for the insects

to tiy at night when the weather is warm and the wind favourable. This fact, in connection with the strong probabihty, nay, certainty, that swarms frequently fly at such a height as to be invisible in the daytime, will alone account for their repeated sudden and mysterious appearances in the morning, at other times in the afternoon of bright clear days, in localities, when nothing had been seen or heard of them along the line they had come. It is possible they prefer nights when the moon shines, though they are probably not confined to them; the warmth and wind being the influencing conditions. Obviously, this point is an important item In determining the possible distance to which single flights may extend. Flying two days and a night, say thirty hours, with a moderately strong and long-continued wind, they may pass over a distance of from four hundred and fifty to five hundred miles, and more, before alighting.

As evidence of the locusts' power of prolonged flight, the fact that they traverse seas of considerable width may be stated; though the sea is undoubtedly often a source of destruction of swarms. They have been known to reach the Canary Isles from the African coast; to come into Cyprus from the neighbouring coasts of Asia Minor; to cross over the Red Sea. They have been seen in the Balearic Isles, having come from North Africa, and there are well-authenticated cases of their occurrence at sea. On November 2, 1865, a ship

on the voyage from Bordeaux to Boston, when twelve hundred miles from the nearest land, was boarded by a swarm, the air being filled and the sails of the ship covered with them for two days. The species proved to be Acridium {ScJiistoceixa) peregj'imun. This is a most striking case, for locusts do not Hy with rapidity, being, indeed, as we have seen, chiefly borne by the wind. It is possible some species may occasionally conie down on the water at night, proceeding somewhat after the fashion of " X^oetganofers " when crossing such massesrivers as described by Mrs. Barber—in as to buoy many without being submerged. An account of an occurrence of the kind may be read in Sir Hans Sloane's history of Jamaica, where it is stated that in 1649 locusts devastated the island of Teneriffe, that the)- were seen to come from Africa on the wind, and that, on the way over, they alighted on the water, in a heap as big as the largest ship, and the next day, having renewed their vigour under the influence of the sun, they took flight again and landed in clouds at Teneriffe. De Saussure says the great oceans are, as a rule, impassable to locusts, and that not a single specimen of the tribe Oedipodides has passed from the Old World to the New. Nevertheless, it may be that Acridunn pereg?imnii, of the tribe Acridiides, was originally native to America, and migrated from there to the Old World.

Locusts Enemies.

For dread of their hereditary enemies the locust-birds, the locusts will exert their extraordinary powers of flight; they are thought to travel day and night until completely exhausted, in the effort to elude these arch-enemies' pursuit and attack. But all in vain; sooner or later the birds overtake the locusts, There is the brown swallow-like locust-bird {Glarcola Nordnianni), the locust-eating stork {Ciconia alba), the grey mottled starling (Diiop/iiis cariinadatiis), and others. All these are not only gregarious, but migratory as well, having no fixed habitat, but follow on the trail of the locusts in Africa. The first-named travels in multitudes second only to the locusts themselves, and are in every respect built for rapid flight. Coming up with their prey, according to their favourite mode, the)' " fall to " at their feast in its passage through the air. While they feed, at the same time they cut ofT with their broad beaks the legs and wings of the locusts they devour, which fall to the earth in curious and novel sight. In stormy weather,myriads—a when pursued by these birds, and they are unable to fly, the locusts seek shelter amongst the shrubs and grasses, creeping into them for concealment; but the birds descend in their train and hunt them up, taking advantage also of them in the morning when they are numbed with cold, and cannot rise.

It is upon the " Voetgangers " the various species of locust-birds depend for food for their young, not upon the winged imagoes, which are never stationary. Ascertaining to a certainty the locality where the locusts have laid their eggs, the birds there, for the time being, take up their abode. By the time the process of nest-building and incubation is accomplished, the young locusts have likewise made their appearance, so that there is abundance of food for the young birds. But occasionally the latter are fledgeddire calamity o'ertakes them—ere the " Voeteaneers " have started on their travels to the north. In most cases, when the locusts have arrived at maturity, and take wing, the locust-birds are ready to accompany them, and together, enemies and prey, they vanish on their wanderings.

Blackbirds, the Prairie hen {Cnpidonia ciipidd) and quail (Ortyx virginianus), and the Plovers, are all efficient workers in the destruction of locusts in America; the Himalayan Black Bear, the skunk, squirrels, mice, frogs, and lizards, may be mentioned among other vertebrate animals more or less useful as locust destroyers. In Africa, in seasons of famine, when the hordes have swept over the earth, all creatures, including the human races of the South, take to a locust diet. But, excepting to the feathered tribes, it proves by no means wholesome food.

Invertebrate Enemies.

Insect and other minute enemies and parasites aid very materially in this destructive work. Many of the larger species of Ground beetles (Carabidae) are most active pursuers and devourers of the locust. The swift-running and flying Tiger beetles (Cicindelidse) have predaceous habits and similar tastes. One would hardly imagine that their stationary larvae, living within cylindrical holes, and entrapping any unwary insects that may chance to come within reach of their formidable jaws, could succeed with such an active creature as the locust. Yet the young locusts fall victims to the larvae; they are draesfed to the bottom of the burrow, and devoured. Asilus flies are also particularly fond of them, pouncing upon and carrying them off to some nook where, unmolested, they can suck their juices. Digger Wasps catch them and paralyze them with their sting, and drag them into the holes they have dug in the soil, which are thus provisioned with food for the subsequent use of their larvae. Scorpions make away with large numbers both of the " Voetgangers " and adults. They hunt by stealth; and on hot, sunny days, when the locusts are feeding, lie in wait and spring upon their prey, after which it is con-veyed to their dwelling-places beneath the rocks. Trap-door spiders, when a swarm passes by, will suddenly

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