ELECTRON MICROSCOPY 



1719 



in the pigmeut-proteiii-lipide complex had occurred during separation; 

 however, the product was "intact" to the extent of still giving a strong Hill 

 reaction (reduction of ferric oxalate with the liberation of oxygen in light). 



P'ig. 37A.3. Electron niiciograph of 

 a maize chloroplast (unshadowed). 

 The darker circular areas are the grana 

 (after Vatter 1952). 



Fig. 37A.4. Electron micrograph of a 

 maize chloroplast showing grana (shad- 

 owed). From fifty to two hundred grana 

 may be present in one plastid (after Vatter 

 1952). 



Fig. 37A.5. Electron micrograph of the edge of a maize chloroplast exposed 

 to Os04 vapor after isolation prior to drying. Folded "blebs" or "vesicles" are 

 common in materials prepared by this method (after Vatter 1952). 



Perhaps the band shift was only an apparent one, caused by diminished 

 scattering. 



A drop of the chloroplast suspension was placed on a plastic film spread 

 over a fine wire mesh and dried. Under the electron microscope (without 



