Locusts are always to be found in Algeria, in the provinces of Oran, Bona, Algiers, and Bougia, but they never commit those terrible ravages which change cultivated countries into deserts. There are in Algeria years of locusts as there are with us years of cockroaches, of blight, of caterpillars, &c. These plagues are fortunately rare. The most terrible took place in 1845 and in 1866. In the former year a formidable invasion of locusts took place. It lasted five months, from March to July, each day bringing new bands of these devastating insects; and M. Henry Berthoud, then in Algeria, saw a column of them, whose passage began before daylight, and had scarcely ended at four o'clock in the afternoon. Dr. Guyon, doctor to the army, and correspondent of the Institute, addressed to this learned body an account of a few peculiarities of this invasion, of which he was a witness. He speaks of a band which passed on the 16th of March over the plain of Sebdon, going in the direction of the desert of Angard. Their passage lasted three hours. The locusts, having found nothing to devour in the desert, came back again, and next day made a descent upon the plain of Sebdon, which is 30 kilomètres long, by 12 to 15 kilomètres broad. In four hours all the crops were devoured, and all vegetation destroyed. "The locusts," says the Doctor, "left behind them an infectious odour of putrid herbs, produced by their excretions." At Algiers, in the Faubourg Bab-Azoum, they penetrated in masses into the barley stores, and there was the greatest difficulty in driving them away, great barricades being raised before the storerooms to stop the invasion. In 1845 they penetrated into the pits in which the natives preserve their wheat. According to the report of the Commandant de la Place of Philippeville, M. Levaillant, a column of locusts alighted in the country round about that town on the 18th of March, 1845, which extended from 30 to 40 centimètres, and the locusts were found heaped upon the ground to the height of three décimètres.