531 



John A. Bergeron 



f 



/ 



A 



9. 4 ^^ m 



f 





Fig. 3. An electron micrograph of an axial section 

 of Anacystis nidulans . The cortex is incompletely 

 partitioned by three concentric membranes spaced 

 about 500 I apart (scale = 1 ^). 



