��Popular Science Monthly
��days the manure is taken down to the beds and less fragile than the first, and the gray, where it is carefully heaped in ridges along This last has a rich odor, but the deep color
galleries with rough walls. Small acquired at a late stage of growth
bricks or "leaves" of mushroom ^ --.,^^^ lowers its price in the markets.
spawn are inserted in holes ^^ ^\ The "sets" of spawn intro-
��made in the ridges. The growth of this spawn, called by botanists ' 'mycelium, ' ' is checked by dryness and quick- ened by humidity and heat. The spawn throws out threads which spread in all directions and finally fill the entire ridge of manure.
Mushrooms Require As Much Care As a Baby
The skill of the cul- tivator reveals itself in adjusting local con- ditions to the require- ments' of his beds. The chief difficulty arises from the enor- mous amount of air absorbed by mush- rooms. They die of suffocation easily. Not only must the galleries be thoroughly ven- tilated, but the air must be moist and changes of temperature must be avoided. Verily, young mushrooms are frail.
The three kinds grown in the under- ground beds around Paris are: the white, which is small and delicate in flavor but does not bear transportation well; the light yellow — stronger, more productive
���Entrance to a subterranean mushroom bed near Paris. In many places aban- doned quarries are utilized in this way
��duced into the manure de- generate after a while, so that raisers seldom cultivate from one seeding more than two or three years. They prefer to take fresh spawn obtained by scientific methods which allow a selection of mushrooms, and then to reproduce the best by direct germ- ination of the spores.
There are in the De- . partment of the Seine two hundred and fifty mushroom-beds, some of great extent, owned by eighty proprietors; the annual value of the yield near Paris is about $2,500,000. Other vegetable growths also receive subterranean cultivation both in other parts of France and elsewhere. French and Belgian market gardeners grow certain vegetables out of season and blanch them underground, one of the most curious exam- ples of the method being the cultivation of wild chicory, a form of endive. Celery and plants of similar nature are also grown and blanched underground.
���Cutting potato sprouts with pruning shears after three weeks of growth in the underground molds. About three months later the potatoes are large enough to be marketed