TABLE 1.

Chemotactic responses of filamentous E. coli cells compared to those of normal-sized E. coli cells

Cephalexin treatment	Mean length (μm) ± SD	Mean no. of tumbles or stops/10 s ± SD	With 5 × 10−5 M l-serine				With 1.5 × 10−2 M sodium benzoate
			% of motile cells responding	No. of tumbles or stopsa	Running speed (μm/s)a	Adaptation time (s)b	% of motile cells responding	Nature of tumbling or stoppingc	Adaptation time (s)d
−	1.5 ± 0.2	7 ± 2e	100	0	19 ± 2	240	100	Continuouse	50
+	7.5 ± 1.2	6 ± 2f	100	0	11 ± 2	90	100	Continuousf	30

^aDuring the first 60 seconds. 

^bAppearance of first tumbles. 

^cDuring the first 10 seconds. 

^dAppearance of first runs. 

^eTumbling, no stopping. 

^fStopping, no tumbling.