Methyl cellulose and bacterial motility

In a previous publication (1946) bacterial motility was shown to be due, not to activity of so-called "flagella, " but to a gyrating and undulating movement of the bacterial body itself. "Flagella " are not motor organs but rather for-tuitous appendages. The gyrating and undulating movement of the bacterial body originates in the protoplasm which lines the inner surface of the cell wall. It forces the cell wvall into the shape of a moving spiral. As a result, the outer covering of the cell wall, which consists chiefly of polysaccharide material, is during fast movement, wvith the added effect of friction, mechanically twisted into a tail as in figure 1. This has been described, photographed, and filmed by me on previous occasions (1930, 1931-32, 1938, 1940, 1941a, 1941b, 1942). At other times this twisted material untvists into a varying number of wavy threads, which have so far gone under the name of "flagella. " These twvistings and un-twistings have up till now only become visible wvith sunlight dark-ground micros-copy (1938, 1940, 1941a). All this not only fits in with modern conceptions of bacterial structure, a