184 



Marine Microbiology 



Fig. 4. Distribution of the cells within the sand column after 48 hours 

 transmigration-time and eight days elution-time. Every 5 mm of height 

 corresponds to cell content of lO^/cm^ sand. 1 = highest, 5 = lo>\'est sec- 

 tor of the columns. 



Quartzsand (a) after 48 hours transmigration-time 



(b) after 8 days elution-time 

 Seasand (c) after 48 hours transmigration-time 

 (d) after 8 days elution-time 



