Behaviour of a Suspension of Microbes 



183 



log KG 



I ml . 



10®: 



10" 



10" 



10": 



10'^ 



Filtration 



oo — oo— o 



•X X— X 









Stamm HI8b 



lim- Quartz sond 



o o lim - Seasond 



X X mar - Quartz sand 



^ £^mar Seasand 



AKG lim 8,3 X 10' 

 AKGmar l,2x 10 



30' l' 2'3V6'l2'24'48' s' 



30'=minutes T: hours l''': dQys(be»ter |d ) 



30' 



2'^3'^5*' 



r2 3 58 log Zeit 



Fig. 

 and 



3. Strain H, 8b. Behaviour during filtration and elution under marine 

 limnic conditions. Abscisse: log time. Ordinate: log living cells/ml 



water. 



( limnic/marine conditions) was low with the small cells of 

 Micrococcus B/lc. It was high with Serratia for both sediments, 

 with Nocardia for qiiartzsand and with strain H/8b for seasand. 



Only Serratia had, under marine conditions, a higher trans- 

 migration-per cent in quartzsand. A comparatixely high number 

 of cells was retained in seasand, though this sediment was more 

 coarse. 



The cells of Serratia and of strain H/8b have nearly the same 

 size but the transmigration-values are quite different in seasand/ 

 marine and quartzsand/limnic. The behaviour of Micrococcus 

 B/lc and of the rods of strain H/Sb may be typical for small 

 cocci and for rods of medium size (Figs. 2, 3). 



Within the sand-column, most of the cells of Serratia, strain 

 H/8b and B. mycoides were retained in the upper 15 cm, especial- 

 ly under marine conditions where the transmigration was lower. 

 The small cells of Micrococcus and the cells of Nocardia were 

 distributed nearly through the column by 48 hours. During the 

 second period of the experiment the number of cells was lowered, 



