The significance of such a conclusion is manifestly obvious. It confirms and gives added force to the observations that man can profitably maintain nitrogen equilibrium, and body-weight, upon a much smaller amount of proteid food than he is accustomed to consume. It harmonizes with the view that the normal requirements of the body for food, under which health, strength, and maximum efficiency are best maintained, are on a far lower level than the ordinary practices of mankind would lead one to believe. The widespread opinion that a rich proteid diet, with the correspondingly high rate of proteid metabolism, is a necessity for the preservation of bodily strength and vigor, is seen to be without foundation; for even the most conservative estimate of the real value of these strength tests must carry with it the conviction that lowering the consumption of proteid food does not at least result in any weakening of the body. This is a fact of vital importance, for it needs no argument to convince even the most optimistic that while it might be possible to maintain body-weight and nitrogen equilibrium on a small amount of proteid food, such a form of physiological economy would not only be of no advantage to the individual, but would be positively injurious if there was a gradual weakening of the muscles of the body with decrease of physical strength, vigor, and endurance. Another fact to be emphasized in this connection was the conviction, gradually acquired by many of the subjects, that they suffered less from fatigue after vigorous muscular effort than formerly. This was especially conspicuous in the case of Donahue, whose work on the Varsity basket-ball team called for vigorous exercise. It is interesting to note that this athlete, of 63 kilos body-weight, for the last four months of the experiment showed an average daily katabolism of 7.45 grams of nitrogen, corresponding to a breaking down of 46.5 grams of proteid material daily. Yet, with this low rate of proteid exchange, he maintained his position on the team with satisfaction to all, and with the consciousness of improved physical condition and greater freedom from fatigue. Other subjects, as the laboratory workers of the professional group, observed that the customary late afternoon fatigue, coincident with the continued walking and standing about the laboratory, gradually became far less conspicuous than usual; so that there seemed to be a consensus of opinion that in some way the change in diet was conducive to greater freedom from muscular weariness.