Decaying vegetable matter, a uniform and rather low temperature, a uniform supply of moisture, – these are the general requisites for Mushroom-growing. The decaying matter is supplied by horse manure. The manure is allowed to heat and is turned several times before it is placed in the bed. The heating itself is probably of no advantage except as it contributes to the decay of the material: heat can be supplied by other means if necessary. The broken and decaying manure is placed a few inches or a foot deep in beds. When the temperature is reduced to 90 degrees or less the spawn is planted. As soon as the bed has cooled sufficiently, it is covered with earth or litter to regulate the temperature and moisture.