As has been stated, this division of organic foods includes those foods which contain too much nitrogenous material to justify their classification among the carbonaceous foods, and too much carbonaceous material to justify their classification among the nitrogenous foods. For example, such a cereal as rolled oats, with its 16.7 per cent protein, cannot surely be classified among the carbonaceous foods, because these, as a rule, do not contain more than four or five per cent of protein at the most, while many of them contain only a small fraction of one per cent. On the other hand, rolled oats should not be classified with the proteins because they contain over seventy per cent of carbonaceous material, mostly carbohydrates. These carbo-nitrogenous foods have been called perfect or complete foods, because they satisfy all of the requirements of the body, and one could live for an indefinite period on any one of these complete foods. A young animal can get sufficient protein from cereals to provide all the necessary material for the growth of any tissues of the body. Furthermore, he can get from the cereals all the carbonaceous material necessary for body fuel. In a similar way legumes or nuts or milk will furnish all the food materials necessary to maintain life and all of the functions of the body for an indefinite period. It is, however, exceptional for human dietaries to be reduced to such great simplicity; even when cereals are freely used there is uniformly a large admixture of milk, eggs, fruits, and vegetables.