Presently we turn to the right, and a scene like a vast subterranean rock temple presents itself. At one end are several of us with lamps, admiring the young mushrooms budding all over the rows of beds, which, serpent-like, are long and slim, and coil away into the darkness. At about 150 feet distance there is a group of three men and a boy, each with a lamp, again dispelling the darkness from the mushroom beds, and occupied in placing small quantities of a sort of white clayey sand in the spots whence gatherings have been made a few hours previously. From both sides of this gloomy avenue the dark openings of others depart at short intervals, and the floor of all is covered with mushroom-beds, sometimes running along the passages, sometimes across them. These beds are about twenty-two inches high and as much in diameter, and are covered with silver sand and a sort of white putty-like clay in about equal proportions. Running along in parallel lines, and disappearing from view in the darkness, one knows not what to compare them to, unless it be to barked pine trees in the hold of a ship. Everywhere on the surface of these little beds small mushrooms were peering forth in quantity; as the beds are regularly gathered from every day, no very large ones are seen. They are preferred when about the size of a chestnut, and are removed root and branch, a small portion of finely sifted earth being placed in each hole, so as to level the bed as in the caves at Montrouge. If the old superstition that a mushroom never grows after being seen by human eyes were true, the trade of a champignonniste would never answer here, as the little budding individuals come within view every day during the gathering and earthing operations. The most perfect cleanliness is observed everywhere in the neighbourhood of these beds, and the whole surface of each avenue is covered by them, leaving passages of ten inches or a foot between the beds. At the time of my visit (Sept. 29, 1868) the crops of the cultivator were reduced to their lowest ebb, and yet about 400 lbs. per day were sent to market. The average daily quantity from this cave is about 880 lbs., and sometimes that is nearly doubled. In some parts of the cave the work of ripping out the stone by powder and simple machinery continually goes on. The arches follow the veining of the stone, so to speak; their lower parts are of hard stone, the upper ones of soft, except the very top, which is again hard. There is but a slight crust of stone above the apex of each arch, and above that the earth and trees. It may be supposed that the profits from such an extensive culture are great; and so they are, but the expense is great also. The proprietor informed me that culture on a more limited scale than he pursued last year at Méry gave the best return in proportion to expense, the care and supervision required by so many miles of beds being too great. [Illustration: Fig. 24. Extracting the stone in subterranean quarries.]