McKay (3) has described the physical condition of the habitants of different parts of India, and correlated this with the character of their diets. His observations leave no room for doubt that the pastoral tribes are vastly superior in strength and health and manly qualities generally, to other classes of Indians. In those parts of India where the diet is largely derived from cereals the physical development of the people appears to be poorest. The rice eaters of Bengal are the most extreme example. The details regarding the components of the diets of the different classes studied by McKay are not sufficiently complete to serve our present purpose as well as we would wish, for he was interested primarily in the amount of protein which the different diets supplied. At the time his book was written, it had been hastily concluded by investigators that science had revealed all the facts necessary for the rational control of diet, and that it remained merely to determine certain minor principles which could contribute to physiological well-being. It was not deemed of importance in his elaborate investigation, therefore, to list the individual foodstuffs eaten and their quantitative relations. To-day this is regarded as the most essential thing to know, when we are called upon to evaluate a dietary regimen. McKay's studies, based upon personal observations, and on the reports of officers of the British Army to their Government concerning the fitness of the men in different parts of India for military service, forms one of the strongest confirmations of the applicability of the principles of nutrition discussed in this book to human experience.

The sour milks used so extensively throughout the East are variously designated sheneena, leben, yohourt, keffir, koumiss, matzoon and dadhi, and are derived from milk of goats, camels, sheep, cows or mares. The fermentation is not purely a lactic acid formation through transformation of the milk sugar, but includes an alcoholic fermentation as well. All these sour milks contain not only a relatively high acidity due to lactic acid, but more or less alcohol as well.