In the light of what has been presented in this chapter it will be readily appreciated that in the past the vegetarian diet has been discussed from the wrong perspective. It is possible to make a fairly satisfactory diet of foods entirely derived from vegetable sources, but it is not easy to do so. In general, a vegetable diet will be markedly improved by the inclusion of muscle tissue meats, and more so by the addition of glandular organs, but even these features of the subject are not from the standpoint of good nutrition the most important. It is scarcely practicable for man to eat enough leafy foods to enable him to succeed with the strictly vegetable diet. The limiting factor is the amount of leafy food which can be consumed. Lack of sufficient calcium is one of the most important deficiencies in such a diet, and a great abundance of leaf is necessary to supply this element in adequate amounts.