If one examines the writings of those of to-day who are most active in studying the health problems of children and in arousing the nation to activity in their behalf, one finds various causes assigned for existing conditions. All would agree that we must attribute our physical deterioration to subjection of the human race to new and unfavorable conditions, but differences of opinion exist as to the nature and relative importance of these. The sedentary life; the life within houses instead of out of doors; the wearing of clothing instead of exposing the skin to the weather with its changing conditions; the eating of soft cooked food instead of raw coarse food; the debilitating effects of certain climates; the preservation of weaklings through improved hygiene and care; the artificial feeding of infants instead of nursing; the burden of responsibilities of civilized life, both mental and moral, and the failure to care for the hygiene of the mouth are among the causes most prominent. Doubtless each of these plays its part in contributing to place civilized man in many parts of the world in his present unenviable position with respect to health. It can now, however, be asserted with assurance, that the chief factor responsible for human deterioration in recent times is not included in the above list. The chief factor lies in the unwise choice of food.