"Casing the beds... consists in covering the beds with an inch to an inch and one-half of good soil, the same kind of soil as is used for mixing in with the manure. The object in casing the beds with soil is to retain the temperature within the material, which is necessary for the maintenance of the growth and it also provides a firmer and cleaner substratum in which the stems of the mushrooms are mostly formed and they are thus cleaner when picked. In from six to seven weeks mushrooms should begin to appear."