ON VARIATIONS IN THE WHITE-CELL COUNT OF MAN

1. Under conditions of moderate activity the large fluctuations in the total white-cell count described by Sabin, Cunningham, Doan , and Kindwall have not been observed. These large fluctuations seem to be due principally to errors of method. The total white-cell count shows, however, small fluctuations, not exceeding ±8 per cent., throughout the day; these persist even after all errors of method have been allowed for. 2. These small fluctuations show no definite periodicity. 3. The increase in the total white-cell count during the afternoon is an inconstant although fairly frequent phenomenon. 4. The increase which sometimes occurs during the afternoon and the smaller fluctuations which occur at short intervals are not due to the production of new polymorphs, but to a redistribution of white cells, i.e. to an alteration of the partition of white cells between the vessels of various parts of the body or between the vessels and the tissue spaces.