The deficiencies of muscle meats are entirely made good by the addition of blood which furnishes the common salt which is nearly lacking in muscle, and by such glandular organs as liver, kidney, etc., which furnish a relative abundance of all three of the uncharacterized dietary factors, the anti-ophthalmic, anti-neuritic and anti-scorbutic substances. Bone furnishes calcium which is not abundant in any other tissues of the body. All carnivorous animals appear to be partial to fat rather than protein as a source of energy and take large amounts of the latter when it is available. The most satisfactory carnivorous diet would appear to be such as is chosen instinctively by the Eskimos and polar carnivorae. All of these as well as those of the cat and dog and rodent families seem to follow the practice of opening the large veins of the neck, when they have killed an animal, and lap the blood as long as it flows. They then open the abdominal cavity and eat of the organs and only after these morsels have been disposed of do they take muscle tissue. It is well known that carnivorous animals have the habit of finishing a repast by leisurely gnawing a bone. Thus they secure a properly balanced diet through selecting parts of their victims which have special dietary properties.