In the neighbourhood of Foix is the Grotto de l’Herme, that has yielded notable finds of prehistoric man. But the main curiosity is the Mas d’Azil, where the river Arize has bored its way through the limestone barrier of the Planturel. This long chain opposed a passage northwards to the river descending from the mountains to the south. The Arize discovered a fault in the barrier and pierced it, forming a noble arch 250 feet high. Beside it is an artificial gallery bored for the passage of the road. The length of the tunnel is 1250 feet. The road follows the right bank of the Arize, separated from it by a wall of rock. The river descends into the gallery, the average width of which is ninety-five feet, breaking over masses of rock that have fallen from the roof. Above the left bank, under the huge vault, rises a natural column, called the Monk. Farther on in the gallery, a pillar thirty feet in diameter sustaining the roof. There are lateral galleries, at a higher elevation, that have yielded evidence of human occupation. The guano produced by the innumerable bats that inhabit the cave actually forms an article of commerce. The opening to the north, through which the river effects its escape, is less striking in appearance than that where it makes its plunge underground. The road from Foix to Ax leads up the river that gives its name to the department, and penetrates deep into the recesses of the mountains. The first town reached is Tarascon, prettily situated at the junction of the Vicdessos with the Ariège, about a conical hill surmounted by a round tower, which is all that remains of a castle that was blown up by order of Richelieu. The great cardinal thought that the best means of maiming the independence of the nobles, petty barons, and seigneurs, was to destroy their nests. It was he, not the Revolutionists, who made the worst havoc among the stately châteaux of France. He went so far even as to insist on the pepper-castor roofed round towers at the angles of every small squire’s mansion being lowered a story to the level of the eaves of the main roof. Tarascon on Ariège is a busier place than sleepy Tarascon on Rhone, that was drawn out of its obscurity by the mythical Tastarin. It is the great centre of activity to the country, “a land whose stones are iron.” Formerly it was more prosperous than it is to-day. But the population remains stationary, which in the midst of a universal shrinkage may be reckoned as good. The town is divided into two parts. Old Tarascon clusters about the decayed castle. New Tarascon forms the faubourg Sainte Quitterie, where there is a ferruginous spring bearing the name of the saint, and supposed miraculously to cure insanity. The wonder in this part of the mountains is to find any springs that do not run red. Quiteria, who has given virtue to this spring, is a person of problematical existence. Once upon a time--the Bollandists even know not when--there