FIGURE 3.

Electron micrograph of a mixture of two E. coli B/r cultures prepared by agar filtration. The big cells were grown in trypton broth with a doubling time of 22 min; the small cells were grown in synthetic alanine-medium with a doubling time of 150 min. Compare with a similar preparation of mixed populations in Figure 2 of Nanninga and Woldringh (1985).