The eyeless cavern spider (_Stalita tænaria_), with brownish palpæ and a snow-white abdomen, is not seldom found in the hollows of the stalactites, lying in wait for the unfortunate Leptodirus. On the surface of the earth spiders are frequently obliged to fast for a very long time; but in caverns where life is so sparingly distributed, the patience of the Stalita must be exemplary, even among spiders. Her appearance on the snow-white stalactital columns, where she only becomes visible when illumined by the full light of a taper,[21] is very striking. Like a vision, she sweeps away in her ivory robe, accompanied by her increasing shadow, until she finally disappears in the darkness. Footnote 21: Torches are not allowed to be carried in the Grotto of Adelsberg, that the whiteness of the stalactites may not be tarnished by the smoke. [Illustration: THE PROTEUS AGUINUS.] But the largest and most interesting of all the European cave animals is undoubtedly the Olm (_Proteus anguinus; Hypochthon_). This enigmatic reptile was first found in the famous Lake of Cirknitz, which, communicating with numerous subterranean caves, alternately receives and loses its waters through openings in the rock. After long and heavy rains the floods, which the hidden vaults are no longer able to contain, gush forth in foaming cataracts, and the lake, which generally forms but a long and narrow channel, then swells to at least three times its ordinary width. Sometimes, after a long drought, the contrary takes place, and the whole lake disappears under ground. Thus, from December 1833 to October 1834, not a trace of it was visible, so thoroughly had it concealed itself in its subterranean reservoirs, where its fishes, secure from the persecutions of man, multiplied in a remarkable manner. The Olm, which only casually comes to the light of day, along with the overflowing waters of the Cirknitz Lake, was first discovered in 1814, in one of its permanent subterranean abodes. The Magdalena or ‘Black Grotto’ situated about a league to the north of Adelsberg, slants abruptly into the bowels of the mountain. After a long and difficult passage over blocks of stone or through soft mud, a tranquil pool is at length reached, which rises or falls simultaneously with the waters of the Poik, and proves, by this reciprocal action, that, in all probability, all the numerous grottoes and subterranean river channels of this so strangely undermined country form but one vast and intricate network. It was in this pool, which no light illumines and no wind ever stirs, that numerous Protei were first discovered; but as hundreds of specimens have since found their way to the cabinets of naturalists, to be observed, dissected, or bottled up in spirits, their number has very much decreased, and the time is perhaps not far distant when they will be entirely extirpated in the grotto, where from time immemorial they had enjoyed an undisturbed security. The Proteus is one of those