mixed group of SBs consisting of 
 plate-like, spherical and irregular SBs 
 (pinealocyte of a guinea-pig kept 
 under normal light conditions, i.e. 12 h 
 light - 12 h darkness, light on at 6.00 am) | 
"paired ribbon field" = group of SBs opposite 
 to each other on the cell membranes of 2 
 adjacent pinealocytes. Note the shield-like 
 stucture of the SBs (guinea-pig kept under 
 constant illumination for 4 months) | 
greater, lump-like, bizarre SBs 
 facing each other and being attached 
 to the plasmalemma of 2 neighbouring 
 pinealocytes (guinea-pig kept under 
 constant illumination for 4 months)  |