Following the proposition of prof. I. Schmalhausen, I have investigated the individual growth of Paramaecium caudatum.
Individuals displanted separately, were measured in living state from one partition to another, with a micrometer. The measurements were done every three hours. Thus 42 individuals were measured. On the fig. № 1 the curve of growth in microns is marked, on the absciss the three hours intervals of time. The greatest intensiveness of growth falls on the first three hours. In order to clear up the details of the rapidity of growth during these first three hours, I have done measurements every half an hour as is represented by the curve № 2. Lastly, I have made calculations of the increase of length in procents not in relation to the original size, but to the previous measurement. On the fig. № 3 the results of these calculations are represented. Here the curve suddenly arises till 23% then rapidly falls, and farther gradually descends.
