TABLE 1.

Percentages of cells of the four different categories at selected time points after phagocytic uptake of particles^a

Phagocytic particle	Time after uptakeb	% Cells of categoryc:
		1	2	3	4
None	NAd	18	82	0	0
B. subtilis	45 min	20	80	0	0
Latex beads	2 h	18	82	0	0
M. smegmatis	1 day	23	77	0	0
M. avium	2 h	24	76	0	0
	1 day	0	21	79	0
	2 days	0	2	38	60
	6 days	0	0	0	100

^aFor each particle and time point, counts were made on Mφs in triplicate monolayers. Each value represents the mean of three determinations on 200 cells each. The standard error of the mean was between 5 and 10%. Data are from a typical experiment. 

^bUninfected cells were cultured in parallel to M. avium-infected ones, and counts were done at the same time points for both cases. The data were taken on day 6. Identical results were obtained at all other time points. 

^cCategories were defined according to the morphological state and distribution of actin filaments (Fig. 1). 

^dNA, not applicable.