habitation for itself. The body must waste when the life-force acts through it, and that waste must be restored by food and sleep, or the body will die; since things (the body) cannot act as the medium of conveying forces (zoo-dynamic or the life-force) without wasting under their action. But so beautifully has the body been made by zoo-dynamic that it wastes very little, much less than is commonly supposed, by the action of zoo-dynamic through it. Not seeing this, we ingest into the body far more than is required to restore its waste, and so we fall ill, for, obviously, if we ingest more than the quantity necessary for this purpose we choke the body up and render it inefficient for its purpose as an instrument for work. Now this is precisely what seems to me to happen in life. As we are all under the double delusion that the strength of the body and its heat come from the food, we all with one accord put far too much food into the body, and when we find that we die, all of us, generation after generation, at from 50 to 70 years of age, we make up little proverbs to justify our unphysiological conduct and say that three score years and ten are the measure of the duration of life. M.D. says that "some twenty years ago most people lived fairly close to the old physiological quantities" (but what are these? for we have seen how they vary), "now they have been cut adrift from these and are floundering out of their depth." May I remind M.D. that people are now living longer than they did twenty years ago. How does he account for that? No doubt some of the increase in the length of life is due to the diminution of the birth rate, but still I suppose M.D. would admit that there is an increase in the duration of life over and above what can be accounted for in this way. If so, how does he account for it? M.D. says, further: "For the public it will now probably suffice if they insist on raising (or considering, A.R.) the question of quantity" (of food, A.R.) "wherever they suffer in any way." I agree with all my heart. But M.D. implies, if I read him aright, that the public should increase the quantity of their food when they suffer in any way. I, on the other hand, and rather unhappily for myself, am convinced that the raising of this question implies that it should be answered in the exact opposite way to that of M.D. and that we should diminish our food if we "suffer in any way." And I can point to Nature's own plan as a corroboration of the truth of my view, for her plan when we suffer in any way is to fling us into bed and take away our appetite, or at least to diminish our appetite if we are not so ill as to require to remain in bed.