The rate of travel varies according to circumstances. With an unfavourable wind, or little wind, they seldom travel more than five miles an hour. At other times, when the wind is favourable, they will cover fifteen to twenty miles per hour. When on the wing it is certain that a distance of 1,000 miles may, in particular cases, be taken as a moderate estimate of flight, and whilst, probably, it is often much less, it is sometimes much more. Their height of flight has been variously estimated at from forty to two hundred feet. "A dropping from the clouds" is a common expression used by observers when describing the apparition of a swarm. It will not be denied that the presence of locusts in force constitutes a terrible plague. They make their appearance in swarms and eat up everything. It is wellnigh impossible to estimate the number in a cloud of locusts, but some idea may be formed from the fact that when they are driven, as sometimes is the case in a storm, into the sea and drowned, so many are washed ashore, that it is said by one observer that their dead bodies formed a bank of nearly 40 miles long and 300 yards wide, and many feet in depth, and the stench from the corruption of their bodies proceeded 150 miles inland. When a swarm of locusts temporarily settles in a district, all vegetation rapidly disappears, and then hunger urges them on another stage. Such is their voracity that cannibalism amongst them has been asserted as an outcome of the failure of other kinds of food. Locusts have their natural enemies. Many birds greedily devour them, in fact a migratory swarm is usually followed by myriads of birds, especially sea gulls; they are often found 150 to 200 miles inland. Often a flock of gulls will clean up a "manga" of locusts; they devour them by thousands, and will then go to a neighbouring laguna, take a little water, and throw up all they have eaten, and at a given signal go off again to fill up with more locusts, only to repeat the operation time after time. Predatory insects of other orders also attack them, especially when in the unwinged state. They have still more deadly foes in parasites, some of which attack the fully developed locust, but the greater number adopt the more insidious method of attacking the eggs. Many inventions have been brought out with the object of exterminating the locusts, some of which, at least, have doubtless been partly successful, but determined and combined effort by the nation and land proprietors is imperative if the remedial and preventive measures proposed are to reap the success hoped for. The Agricultural Defence Department reports having spent $10,561,540 mn. from 1st January, 1909, to 31st May, 1910, in fighting the locusts. The total area invaded was 135,000,000 hectares (about 337,500,000 acres). From 1892 to date, and with what is required for the present year, $54,000,000 have been spent in combating locusts and like plagues to agriculture.