Legumes are the seeds of a certain group of plants grown in pods. The term comes from a very ancient word, "legere," meaning to gather. Beans and peas are the most familiar types of this group.

Legumes are rich in nitrogen, and some varieties are also very rich in oil. They are not equal to nuts in fuel or food value, however, because in the natural state they are hard, somewhat indigestible, and unpalatable. These qualities are due to the fact that the nitrogenous material of legumes are radically different from the nitrogen found in nuts, and belong to a class not so desirable as food. Meat may be omitted from the diet and legumes adopted as the chief source of nitrogen, but this change requires some knowledge and careful feeding in the beginning. Meat is digested wholly in the stomach and does not require mastication (only enough to be swallowed), while dried or mature legumes require much mastication, owing to the carbohydrates they contain. The best form in which legumes can be taken is in their green or immature state, owing to the fact that the immature starch they contain is readily soluble, while mature legume starch is rather difficult to digest.