Fungi are sometimes described as "vegetable, steak, and roast beef," and the poor are urged to eat them for economy. This is an exaggerated estimate of their value. It is true that they contain a large amount of nitrogenous matter; a considerable percentage of it, however, is not protein. They contain a small amount of carbohydrate, the exact nature of which is not understood, but which is not believed to be nutritious. Their abundant framework of cellulose helps to make them indigestible. When cooked, they contract and become tougher. From 30 to 50 per cent, of the protein in them is not digested or absorbed from the intestine. They must, therefore, be classed with other wasteful foods. They are not adapted to the use of most invalids, but have the valuable quality of adding variety to the limited list of foods that may be eaten by diabetic patients. They are also agreeable additions to the dietary of the healthy. The amount of protein in different varieties of fungi varies from 2 to 5 per cent.

The differences between edible and poisonous mushrooms and other fungi will not be described here. Of the many hundreds growing in this country, only a few are commonly eaten. Excellent descriptions of these will be found in Bulletin No. 15 of the United States Department of Agriculture.

The only algae commonly employed as a food is Irish moss.

Its chief ingredient is a mucilaginous substance that can be dissolved or softened by hot water, and, when cooked, becomes a yellowish jelly. It is not acted upon by any of the digestive ferments and probably has no value as a food. It is bland and soothes an irritable throat, stomach, or intestine. Sugar and cream may be added to it or eaten with it. It is a pleasant addition to the limited dietary of diabetics.

Iceland moss is a lichen that is used by cooks, as Irish moss is. It is likewise without value as a food.