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y 





PLATE II. Sectioned cell of E. co/i. Note bacterial wall (w) and plasma membrane (p). The cell 

 is packed with ribosomes except in the nuclear region where DNA-containing fibers are seen. No 

 nuclear membranes or membranous cytoplasmic organelles ore apparent. 53,000 X- (Courtesy of 

 E. Kellenberger.) 



