529 



John A. Bergeron 



Fig. 1. Dark field fluorescence 

 micrograph of extracted Anacystis 

 showing nonfluore scent axial region. 



I I 



10 

 0.9 

 08 

 07 

 0.6 

 05 



~i I I I I I I — I — I — t — I — I — I — I — I — I — I — I — r 

 ABSORPTION OF ANACYSTIS NIOULANS 

 AFTER CHLOROPHYLL ^EXTRACTION 



10% FORMALIN FIXED 

 80% ACETONE 

 EXTRACTED 



400 460 520 580 640 700 760 

 WAVE LENGTH m^ 



Fig. 2. Absorption spectrum of 

 Anacystis repeatedly extracted in 

 805& acetone after 15 min exposure 

 to 10^ formalin. 



that the red fluorescence 

 of phycocyanin and chloro- 

 phyll is restricted to the 

 cortex of the organism. 

 This is still true -v^en 

 enough chlorophyll has beoi 

 extracted so that the pig- 

 ment is no longer observ- 

 able in the absorption 

 spectrum (Figs. 1 & 2) . It 

 seems appropriate to con- 

 clude that the bulk, if not 

 all, of the fluorescent 

 chlorophyll and phycocyanin 

 is in the cortex. 



This result is not sur- 

 prising since the axial re- • 

 gion of Anacystis resembles 

 the bacterial nucleoid. In 

 our cultures the fine struc- 

 ture of organisms taken 

 from the log phase of 

 growth is typified by the 

 example in Figure 3' The 

 peripheral cytoplasm is in- 

 completely partitioned by 

 two concentric membranes 

 spaced about 500 A apart. 

 There is also present a 

 third incomplete membrane. 

 Employing Figure 3 as an 

 example of an axial section 

 we have attempted to assess 

 whether the cytoplasmic 

 membranes could account fbr 

 all of the chlorophyll and 

 also the effect of limit- 

 ing the phycocyanin to the 

 cortex. Frcm the volume 

 (8.0 X 10~13 cc) calcula- 

 ted for this cell compared 

 with the concentrations 

 calculated for the average 

 cell (volume of I.58 x 

 10-12 cc) this cell would 



