During the visit which the Archduke Ferdinand paid, in 1819, to the Magdalena Grotto, the most remarkable parts of the cave were brilliantly illuminated, so as to produce a magical effect. Charon’s boat, issuing from a dark recess, came gliding along over the black surface of the pool. The grim ferryman drew up his net before the august visitors, and presented them with six Protei that had been entangled in its meshes. Dr. Schmidl mentions part of the subterranean river in the Planina Cave, 1,715 fathoms from the entrance, as the spot where the Protei are most abundant. Near to a small cascade which the rivulet here forms over a reef, the waters absolutely swarm with them, and the light-coloured animals, darting about in all directions in the dark stream, afford a strange and picturesque spectacle. As the cavern is of most difficult access, they here enjoy a tranquillity rarely disturbed, and no doubt they have many other still more hidden retreats, to which man is incapable of penetrating. The best method for transporting the Proteus is now perfectly understood, and living specimens have been conveyed as far as Russia, Hungary, and Scotland. All that they need is a frequent supply of fresh water, and a careful removal of all light. Their food need cause no trouble, as the water contains all they require. It is recommended to lay a piece of stalactite from their native grotto in the vase in which they are transported. When resting or sleeping, they then coil themselves round the stone, as if tenderly embracing it. In this manner they have already been kept above five years out of their caverns. The guides to the Grotto of Adelsberg have always got a supply on hand, and sell them for about two florins a-piece.
On turning our attention from the grottoes of Carniola to those of the New World, we find, in the vast Mammoth Cave in Kentucky, a no less interesting animal creation, which, though different from that of the Austrian caverns, still shows a certain family resemblance, and affords another proof that a similarity of external circumstances always produces analogous forms of organic life. Thus, the two blind beetles which are found in the Mammoth Cave belong to the same genera (Anophthalmus and Adelops) that have also their representatives in the Grotto of Adelsberg. The largest insect is here a species of cricket, with enormously long antennæ; there are also two small white eyeless spiders and a few crustaceans. The Mammoth Cave has no proteiform reptile to boast of, but a peculiar blind rat and a peculiar blind fish.
The cavern rat, which is tolerably numerous, but which, on account of its remarkable timidity, seldom shows itself, differs from the common or Norway rat, by its bluish colour, its white abdomen, neck, and feet, and its soft hair. It has large black eyes, like those of a rabbit, but entirely destitute of an iris, and uncommonly long whiskers, as if Nature had wished to indemnify it for the loss of sight by a more perfect development of the sense of touch. Although the eyes of this rat are large and brilliant, yet Professor Silliman convinced himself of their perfect insensibility to light. All proof is wanting that it ever visits the upper world.
BLIND FISH (AMBLYOPSIS SPELÆUS).
The blind fish (Amblyopsis spelæus) is now become tolerably rare from its having been so frequently fished out of the Lethe stream, as the subterranean river of the Mammoth Cave is called. Many physiologists have already made it the subject of their observations, and are generally of opinion that the Amblyopsis was not originally blind, but that, having found its way into the cave, it gradually lost its powers of vision. The celebrated naturalist Agassiz, however, being perfectly convinced that all animals existing in a wild state have been created within their actual bounds with all the peculiarities of structure which distinguish them at the present day, is of opinion that the blind fish and all the other blind animals of the Mammoth Cave are the aboriginal children of darkness, and have at no time been connected with the world of light.
CHAPTER XV.
CAVES AS PLACES OF REFUGE.
The Cave of Adullam—Mahomet in the Cave of Thaur—The Cave of Longara—The Cave of Egg—The Caves of Rathlin—The Cave of Yeermalik—The Caves of Granada—Aben Aboo, the Morisco king—The Caves of Gortyna and Melidoni—Atrocities of French Warfare in Algeria—The Caves of the Dahra—The Cave of Shelas—St. Arnaud.
In times of war or persecution, caverns have often served as places of concealment. It was in the cave of Adullam that David hid himself to escape from the fury of Saul; and on the flight from Mecca to Medina, Mahomet and his disciple Abu Bekr took refuge in a cave in Mount Thaur. They left Mecca while it was yet dark, making their way on foot by the light of the stars, and the day dawned as they found themselves at the foot of the hill, about an hour’s distance from the holy city. Scarcely were they within the cave when they heard the sound of pursuit. Abu Bekr, though a brave man, quaked with fear. ‘Our pursuers,’ said he, ‘are many, and we are but two.’ ‘Nay,’ replied Mahomet, ‘there is a third: God is with us!’
And here the Moslem writers relate a miracle dear to the minds of true believers. By the time, say they, that his pursuers, the Koreishites, reached the mouth of the cave, an acacia-tree had sprung up before it, in the spreading branches of which a pigeon had made its nest and laid its eggs, and over the whole a spider had woven its web. When the Koreishites beheld these signs of undisturbed quiet, they concluded that no one could recently have entered the cavern, so they turned away and pursued their search in another direction.