Among the starch-producing plants extensively cultivated for food in tropical countries, and which are destined to add immensely to the food-supply of colder climates, are yams, bread-fruit and bananas, including the variety known as plantains. The last family rivals the sago-palm in affording the maximum amount of food for the minimum amount of labor. The yield to the acre is in bulk forty-four times that of the potato, and the proportion of starch is somewhat greater. The fruit is also richer in other elements of nutriment, so that the meal prepared by drying and grinding the plantain core resembles the flour of wheat in food value. It is easily digested, and in British Guiana is largely employed as food for children and invalids. The cost of preparing the food can not be great, and the supply might be unlimited. The proportion of starch is seventeen per cent.; in breadfruit it is about the same; in yams it rises to twenty-five per cent., but is hard to extract, owing to the woody character of the roots.