Sawdust has been used in England for mushroom beds, after having been used for stable bedding, with very good results. It has also been used successfully in the District of Columbia. In fact, the very large models of cultivated mushrooms exhibited by the Division of Microscopy of the Department of Agriculture at the World's Fair in Chicago were moulded from mushrooms which were grown on the writer's premises, in a composition of sawdust stable bedding, combined with about one-fourth garden mould, but I am confident, at the same time, that much depends on the kind of timber the sawdust is made from. In this case the sawdust came from spruce.