The most extensive and successful culture of mushrooms in existence is carried on in widely-ramifying caves far beneath the surface in the vicinity of Paris. To give the reader as good an idea of it as I can we must visit one of the great “Mushroom caves” at Montrouge, just outside the fortifications of Paris, on the southern side. The surface of the ground is mostly cropped with wheat; but here and there lie, ready to be transported to Paris, blocks of white stone, which have recently been brought to the surface through coalpit-like openings. There is nothing like a “quarry,” as we understand it, to be seen; the stone is extracted as we extract coal, and with no interference whatever with the surface of the ground. We find a “champignonniste” after some trouble, and he accompanies us across some fields to the entrance of his subterranean garden. It is a circular opening like the mouth of an old well, but from it protrudes the head of a thick pole with sticks thrust through it. This pole, the base of which rests in darkness sixty feet below, is the easiest and indeed the only way by which human beings can get into the mine. I had an idea that one might enter sideways and in a more agreeable manner, but it was not so. Down the shaky pole my guide creeps, I follow, and soon reach the bottom, from which little passages radiate. A few little lamps fixed on pointed sticks are placed below, and, arming ourselves with one each, we slowly commence exploring dark, still, tortuous passages. I have heard that the first individual who commenced mushroom-growing in these catacomb-like burrowings was one who, at a particularly glorious epoch of the history of France, when a great many more brave garÇons went to fight than returned from the victory, preferred, strange to say, to stay at home and hide himself rather than form a unit in “battle’s magnificently stern array.” Industrious and discreet youth! You deserve being held up as an example as much as the busy bee that improves each “shining hour.”

The passages are narrow, and occasionally we have to stoop. On each hand there are little narrow beds of half-decomposed stable manure running along the wall. These have been made quite recently, and have not yet been spawned. Presently we arrive at others in which the spawn has been placed, and is “taking” freely. The spawn in these caves is introduced into the little beds in flakes taken from an old bed, or, still better, from a heap of stable manure in which it occurs naturally. Such spawn is preferred, and considered much more valuable than that taken from old beds. Of spawn in the form of bricks, such as is used in England, there is none.

The champignonniste pointed with pride to the way in which the flakes of spawn had begun to spread through the little beds, and passed on—sometimes stooping very low to avoid the pointed stones in the roof—to where the beds were in a more advanced state. Here we saw little, smooth, putty-coloured ridges running along the sides of the passages, and wherever the rocky subway became as large as a small bedroom two or three little beds were placed parallel to each other. These beds were new, and dotted all over with mushrooms no bigger than sweet pea seeds, affording an excellent prospect of a crop. Each bed contains a much smaller body of manure than is ever the case in our gardens. They are not more than twenty inches high, and about the same width at the base; while those against the sides of the passages are not so large as those placed in the open spaces. The soil, with which they are covered to the depth of about an inch, is nearly white, and is simply sifted from the rubbish of the stone-cutters above, giving the recently-made bed the appearance of being covered with putty.

Although we are from seventy to eighty feet below the surface of the ground, everything looks quite neat—in fact, very much more so than could have been expected, not a particle of litter being met with. A certain length of bed is made every day in the year, and as the men finish one gallery or series of galleries at a time, the beds in each have a similar character. As we proceed to those in full bearing, creeping up and down narrow passages, winding always between the two little narrow beds against the wall on each side, and passing now and then through wider nooks filled with two or three little beds, daylight is again seen. This time it comes through another well-like shaft, formerly used for getting up the stone, but now for throwing down the requisite materials into the cave. At the bottom lies a large heap of the white earth before alluded to, and a barrel of water—for gentle waterings are required in the quiet, cool, black stillness of these caves, as well as in mushroom-houses on the upper crust.

Once more we plunge into a passage as dark as ink, and find ourselves between two lines of beds in full bearing, the beautiful white button-like mushrooms appearing everywhere in profusion along the sides of the diminutive beds, something like the drills which farmers make for green crops. As the proprietor goes along he removes sundry bunches that are in perfection, and leaves them on the spot, so that they may be collected with the rest for to-morrow’s market. He gathers largely every day, occasionally sending more than 400 lb. weight per day, the average being about 300 lb.

A moment more and we are in an open space, a sort of chamber, say 20 feet by 12, and here the little beds are arranged in parallel lines, an alley of not more than four inches separating them, the sides of the beds being literally blistered all over with mushrooms. There is one exception; on half of the bed and for about ten feet along, the little mushrooms have appeared and are appearing, but they never get larger than a pea, and shrivel away, “bewitched” as it were. At least such was the inference drawn from the cultivator’s expression about it. He gravely attributed it to a ridiculously superstitious cause. Frequently the mushrooms grow in bunches or “rocks,” as they are called, and in such cases those that compose the little mass are lifted all together.

The sides of one bed here had been almost stripped by the taking away of such bunches, and it is worthy of note that they are not only taken out, root and all, when being gathered, but the very spot in which they grew is scraped out, so as to get rid of every trace of the old bunch, and the space is covered with a little earth from the bottom of the heap. It is the habit to do this in every case, and when the gatherer leaves a small hole from which he has pulled even a solitary mushroom, he fills it with some of the white earth from the base, no doubt intending to gather other mushrooms from the same spots before many weeks are over. The “buttons” look very white, and are apparently of prime quality. The absence of all littery coverings and dust, and the daily gatherings, secure them in what we may term perfect condition. I visited this cave on the 6th of July, 1868, and doubt very much if at that season a more remarkable crop of mushrooms could be anywhere found than was presented in this subterranean chamber—a mere speck in the space devoted to mushroom culture by one individual.

When I state that there are six or seven miles run of mushroom-beds in the ramifications of this cave, and that the owner is but one of a large class who devote themselves to mushroom culture, the reader will have some opportunity of judging of the extent to which it is carried on about Paris. These caves not only supply the wants of the city above them, but those of England and other countries also, large quantities of preserved mushrooms being exported, one house alone sending to our own country no less than 14,000 boxes annually. There were some traces of the teeth of rats on the produce, and it need not be said that these enemies are not agreeable in such a place; but they did not seem to have committed any serious ravages, and are probably only casual visitors, who take the first opportunity of obtaining more varied food than is afforded them by these caves. To traverse the passages any further is needless—there is nothing to be seen but a repetition of the culture above described, every available inch of the cave being occupied. We again find our way to the bottom of the shaft, carefully mount the rather shaky pole one at a time, and again stand in the hot sun in the midst of the ripe wheat.

In traversing the fields two things relating to mushroom culture are to be observed—heaps of white gritty earth, sifted from the dÉbris of the white stone, and large heaps of stable manure accumulated for mushroom growing, and undergoing preparation for it. That preparation is different from what we are accustomed to give it. It is ordinary stable manure, or very short stuff, not droppings, and is thrown into heaps four or five feet high, and perhaps thirty feet wide. The men were employed turning this over, the mass being afterwards stamped down with their feet, a water-cart and pots being used to thoroughly water the manure where it is dry and whitish.

As many will feel an interest in the cave culture of the mushroom, and perhaps wish to see it for themselves, I may state that it is difficult to obtain permission to visit the caves, and many persons would not like the look of the “ladder” which affords an entrance. Even with a well-known Parisian horticulturist I had some difficulty in entering them. I was informed that one champignonniste in the same neighbourhood demands the exorbitant price of twenty francs for a visit to his cave. As the visit is the work of some little time, no visitor should put the cultivators to this trouble without offering some slight recompense—say not less than five francs. The above cave is but a sample of many in the immediate neighbourhood of Paris.

We will next visit a mushroom-cave of another type at some little distance from that city. It is situated near FrÉpillon, MÉry-sur-Oise—a place which may be reached in an hour or so by the Chemin de fer du Nord, passing by Enghien, the valley of Montmorency and Pontoise, and alighting at Auvers. There are vast quarries in the neighbourhood, both for building-stone and the plaster so largely used in Paris. The materials are not quarried in the ordinary way by opening up the ground, nor by the method employed at Montrouge and elsewhere in the suburbs of Paris, but so that the interior of the earth looks like a vast gloomy cathedral. In 1867 the mushroom culture was in full force at MÉry, and as many as 3000 lbs. a day were sometimes sent from thence to the Paris market; but the mushroom is a thing of peculiar taste, and these quarries are now empty—cleaned out and left to rest. After a time the great quarries seem to become tired of their occupants, or the mushrooms dislike the air; the quarries are then well cleaned out, the very soil where the beds rested being scraped away, and the place left to recruit itself for a year or two. In 1867 M. Renaudot had the extraordinary length of over twenty-one miles of mushroom-beds in one great cave at MÉry; last year there were sixteen miles in a cave at FrÉpillon. This is a clean, lonely village, just touching on the gigantic cemetery which M. Haussmann projected.

The distant view of the entrance to the quarries has much the appearance of an English chalk-pit. But there is a great rude arch cut into the rock, and into this we enter, meeting presently a waggon coming forth with a load of stones, the waggoner with lamp in hand. To the visitor who has seen the mushroom caves near Paris, where it is sometimes necessary to stoop very low to avoid knocking one’s head against the roof rocks, the surprise is great on getting a little way in. At least it is so soon as one can see; the darkness is so profound that a few candles or lamps merely make it more visible. The tunnel we traverse is nearly regularly arched, masonry being used here and there, so as to render the support secure and somewhat symmetrical, the arches being flat at the top for six feet or so, and about twenty-five feet high; sometimes five feet higher.

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.

All the manure employed is brought from Paris by rail, as the place is twenty-five miles from that city by road. In the first place, so much per month is paid in Paris for the manure of each horse; then it has to be carted to the railway station and loaded in the waggons; next it is brought to the station of Auvers, and afterwards carted a couple of miles to the quarries, paying a toll for a bridge over the Oise on the way. That surely is difficulty enough for a cultivator to begin with! Then it is placed in great flat heaps a yard deep by about thirty long and ten wide, not far removed from the mouth of the cave, and here it is prepared, turned over and well mixed three times, and as a rule watered twice. About five or six weeks are occupied in the preparation, long manure requiring more time than short. The watering is not usually done regularly over the mass, but chiefly where it is dry and overheated. Every day manure is brought from Paris; every day new beds are made and old ones cleared out—the spent manure being used for garden purposes, particularly in surfacing or mulching, so as to prevent over-radiation from the ground in summer. The chief advantage the cultivator here has is the facility of taking his manure or anything else in or out in carts, as easily as if the beds were made in the open air. Near Paris, on the contrary, everything has to be sent up and down through shafts like those of an old well, and the men have to creep up and down a rough pole like mice. Many men are employed in the culture, the daily examination of sixteen miles of beds being a considerable item in itself. Here and there a barrier in the form of straw nailed between laths may be seen blocking up the great arch to a height of six feet or so. This is to prevent currents of air wandering about through the vast passages.

The mode of preparing the spawn here is entirely different to ours. They prefer virgin spawn—that is to say, spawn found naturally in a heap of manure. But as this material cannot be obtained in sufficient quantity to meet the wants of such extensive growers, they put a small portion of it into a mushroom-bed to spread, and instead of allowing this bed to produce mushrooms, it is all used as spawn, and is valued more than any other. Of course abundance of spawn occurs in the old beds, but it is never used directly. It is, however, frequently employed to spawn a small bed when virgin spawn cannot be obtained. In this case the small bed devoted to the propagation of spawn is placed in the open air, and covered with straw, and as soon as it is permeated with the spawn it is carried into the caves and used. As the making and spawning of beds is a process continually going on, a bed of this sort must be ready at all times. It is never made into bricks as with us, but simply spread through short, partly-decomposed, manure.[A]

I was informed that coal-mines are not adapted for growing mushrooms, and the smallest particle of iron in the beds of manure is avoided by the spawn, a circle around it remaining inert. It is said to be the same with coal. If an evil-disposed workman wishes to injure his employer, he has only to slip along by the beds with a pocketful of rusty old nails, and insert one here and there.

The beds remain in good bearing generally about two months, but sometimes last twice and three times as long. A useful contrivance for facilitating the watering of the beds has lately been invented; it consists of a portable water-cistern to be strapped to the back and fitted with a rose and tubing, so that a workman may carry a larger quantity of water, and apply it more regularly and gently than with the old-fashioned watering-pots—while one hand is left free to carry the lamp. An iron frame has also been invented, in which the bed is first compressed and shaped, the frame being then reversed and the bed placed in position. Another invention for earthing the beds over as soon as the spawn has taken will soon be in operation if not already so. As on an average 2500 yards of beds are made every month, simple mechanical contrivances to facilitate the operation will prove of the greatest advantage to the cultivator.

In addition to the caves in the localities above alluded to there are other places near Paris where the culture is carried on—notably at Moulin de la Roche, Sous BicÊtre, near St. Germaine, and also at Bagneux. The equability of temperature in the caves renders the culture of the mushroom possible at all seasons; but the best crops are gathered in winter, and consequently that is the best time to see them. I, however, saw abundant crops in the hottest part of the very hot season of 1868. These mushroom caves are under Government supervision, and are regularly inspected like any other mines in which work is going on. As regards the depth at which this culture is practised, it usually varies from twenty to one hundred feet, sometimes reaching one hundred and fifty and one hundred and sixty feet from the surface of the earth. They are so large that sometimes people are lost in them. In one instance the proprietor of a large cave went astray, and it was three days before he was discovered, although soldiers and volunteers in abundance were sent down. Is it possible that in a great mining and excavating country like ours we cannot establish the same kind of industry?