* * Caves in limestone are usually more or less connected with fissures of the rock in which they exist, and the solid matter that once filled them appears in many cases to have been carried off through the fissures by the long continued and gradual perco¬ lation of water, removing the softer or decayed portions of the rock, either in a state of solution or mechanical suspension, so that no traces of it remain at present either in the caverns or the fissures. I think it highly probable, from the description given by Tournefort, in his Voyage to the Levant, p. 53, and from the map and plan of it published in Sieber's Travels in Crete, 1823, PI. 13, that the celebrated labyrinth of Crete was nothing more than a long connected series of natural caverns, such as we are now considering, a little assisted by art, and by the addition of a few corridors between the natural vaultings that compose this subterraneous wonder of classic antiquity. It is stated to occur in grey stratified limestone, which is found abundantly in Crete, and is full of caves and fissures. " Through the whole island," says Tournefort, " there are a world of caverns, especially in Mount Ida, there are holes you may run your head in, bored through and through, and * For a full explanation of the terms stalactite, stalagmite, and breccia, which I shall frequently make use of, I beg to refer my readers to Dr. Kidd's Outlines of DISCOVERED AT KIRKDALE, IN YORKSHIRE. 9 * Pennant, in his Zoology, (3rd edit. 4to. vol. 1, p. 305) speaking of the Caspian Lynx, mentions one which bit off and devoured one of its own fractured limbs. Rats and foxes, when caught in traps, are often known to bite off their wounded limbs, but I have not heard of their devouring them. * See a good illustration of this in Plate XX., and the description of the cave at the Dream Mine, near Wirksworth, at page 62, et seq. * These blocks lie on the Jura Mountains, at an elevation of 2000 feet above the Lake of Geneva. Their size in some cases amounts, as in the Valley of Monetier, upon the Saleve Mountain, to 1200 cubic feet; and in the case of those on the Coteau de Boissy to 2250, and even to 10,296 cubic feet, which is the measure of the block called Pierre a Martin.