From this rock, which projects over the abyss, the only descent is by means of a rope or a rope-ladder. The bottom of the pit is covered with large blocks of stone irregularly piled up, and here one first sees the river rushing through the cave from right to left. The Piuka Jama may thus be compared to a window pierced through a vault overspanning a subterranean stream. Clambering down a heap of rubbish, the explorer at length stands upon the floor of the cave, and reaches the bank of the Poik. Stream-upwards, about 300 fathoms from the aperture, he meets with a rock gate, through which the river rushes so violently that a boat can master the current only when the water is unusually low. After crossing this broad portal, the last faint traces of daylight glimmering from the distant aperture in the Piuka entirely disappear, and the scene suddenly changes. The expanding cavern assumes the proportions of an imposing dome. On its left side a mound has been formed by the falling in of the roof; but every block of stone is completely covered with calcareous incrustations of the purest white. From the floor to the centre of the vault millions upon millions of brilliant spars reflect the light: every hollow in the walls is a cabinet of gems. The background of the dome completes the beauty of the scene, and exhibits one of the most imposing cavern decorations it is possible to imagine. A monstrous pillar rises from its centre, forming two colossal ogival portals. The larger one is on the left, and at its entrance a mighty stalagmite, above twelve feet high, seems to forbid intrusion. The pillar itself and the vaults of both the portals are ornamented with the richest stalactital drapery. When the river is swollen it rushes tumultuously through both the gates, where now Dr. Schmidl found but a scanty rill whispering and babbling among the stones. CHAPTER XIV. SUBTERRANEAN LIFE. Subterranean Vegetation—Fungi—Enormous Fungus in a Tunnel near Doncaster—Artificial Mushroom-beds near Paris—Subterranean Animals—The Guacharo—Wholesale Slaughter—Insects in the Cave of Adelsberg—The Leptodirus and the Blothrus—The Stalita tænaria—The Olm or Proteus—The Lake of Cirknitz—The Archduke Ferdinand and Charon—The Blind Rat and the Blind Fish of the Mammoth Cave.