The old are subject to certain fluctuations, new in kind, degree, or both. Sleep is less regular. They have good and bad nights, one or more of each alternating, which make the next day clear or cloudy with dregs. If fatigue comes more quickly, so does recuperation by rest. They are often refreshed by a very brief nap or by recumbency, or even by a period of solitude during the day. Thus on the periodicity of day and night is superposed one of less amplitude or briefer duration, perhaps after one or each meal. Thus the distinction between the sleeping and waking state comes to be less sharp, slumber is not so deep or long, and the dreamy states of reverie invade mentation by day. The great restorer does not quite make losses good and the accumulation of these deficits explains very many of the phenomena of old age, which might be characterized as sleepiness for death, the rest that is complete and knows no waking. Capitulation to the siesta habit is marked in some by a distinct improvement of condition. They speak of a new balance between activity and repose and sleep all the better nights, while others resist such tamperings with nature’s rhythm and if they acquire the midday habit find themselves nervous or less refreshed the morning after. Some retire and rise with the sun and find a certain elation of spirits in this reversion to nature and praise the morning hour or even sunrise, of which the urbanized world about them knows little and ever less; while others find a virtue in lying abed late. While we know too little of the hygiene of the aged to prescribe, it is certain that they tend to break with the old regulations and really need some of the indulgences they are often too inclined to permit themselves. The appetites fluctuate and may readily become capricious. Some would eat more and less often than before and love to experiment with new viands. Some think some items of diet once beneficial become harmful and so eliminate them, while some like and can digest things impossible before. Sometimes they indulge for days or even weeks in a favorite dish that at intervals they cannot touch with impunity, as if there were spells of immunity broken by intervals during which the same article produces deleterious results. One says that what is at one time a food becomes for him at another time a poison. This seems particularly true of certain fruits, while the acid balance seems very liable to upsets. Most tend to overeat and are always struggling with their appetite. Yet they often have periods when foods lose their attraction, as if Nature decreed a fast. Here she is often right and a day or more of relative or even entire abstinence may prove helpful. So the former diet periods do not need to be observed; nor need the old be coaxed at such times with tempting food.