When a fresh medium is inoculated with a given number of cells, and the population growth is monitored over a period of time, plotting the data will yield a typical bacterial growth curve (Figure 3 below). Figure 3. The typical bacterial growth curve.
At the same time that overall production was growing, population growth was declining. As can be seen in Figure 3, from an annual rate of increase of 1.85 and 1.93 percent in 1920 and 1921, respectively, population growth rates fell to 1.23 percent in 1928 and 1.04 percent in 1929.