Apart from empty greenhouses altogether, the space beneath the stages in numbers of glass-houses of every type may be utilized for the production of mushrooms. These positions are usually unoccupied, occasionally they are used for storing fuchsias, &c. in winter, but very seldom are they turned to so good account as they might be in the way I recommend. The stage in the small greenhouse is frequently elevated so that there is plenty of room to get beneath it: if at the back or end there is no way of walking readily under the stage, an opening should be made. The only difficulty that could possibly occur would arise from the drip from the plants on the stage above. This, however, can be easily guarded against by spreading a piece of tarpaulin or oil-canvas over the bed or beds. With beds properly made, a coat of dry hay or litter, and a piece of tarpaulin, every owner of anything in the shape of a greenhouse with a stage in it may grow mushrooms throughout the autumn, winter, and spring months, and even in summer by keeping the surface of the hay or litter moist. Of course, if there be room for but one bed, a succession cannot be kept up, and in this case a bed should be made in autumn, which, if well managed, should be in full bearing for a month or six weeks before and after Christmas. There are, however, numerous spaces such as those alluded to where there is room to make a succession of beds. No person having but one greenhouse need fear much or any inconvenience from the odour of the manure--at least, not after the beds are earthed. The couple of inches of soil over the manure would absorb any vapour given off by the bed. Wherever the cultivation of cucumbers or melons in pits or frames is carried out, nothing can be easier than to grow large crops of mushrooms after the melons, &c. are cleared away. The spawn may be inserted over the surface of the little mounds usually made for the reception of the young melon plants, and also over the remaining surface of the beds which are generally covered with a few inches of earth. After the melons have done bearing and the haulm is cleared away, the spawn will usually be found to have spread through the deep mass of earth in the beds. As little or no water is given or required while the melons are ripening, a good soaking of tepid water will generally be necessary to encourage the mushrooms to start into profuse bearing. If the season and situation be mild and warm, the lights may be taken off; and if the sun be very strong, the beds may be shaded with canvas or mats. If the season be late and cold it will, on the other hand, be desirable to keep on the lights, and even to cover them in cold weather. CHAPTER VI. THE CAVE CULTURE OF MUSHROOMS, NEAR PARIS.