Abstract
The diurnal change in circulating eosinophils was studied in four healthy men in the daily routine of laborartory life. The maximal level was obtained at night during sleep, and the minimal in the daytime. Moreover, individual habit seems to play some part in the diurnal rhythm in eosinophils. The second observation of eosinophils in two men with short duration of sleep at night indicated significantly that a continuous sleep might be required for an efficient recovery from stressful performance.
