Behaviour of a Suspension of Microbes 



TABLE 1 



Characteristics of the Sediments 



181 



Sea Sand from the Beach 

 of the Baltic Sea 



Tertiary Quartz Sand 

 from Hohenbocken 



Mineralogical 

 composition 



Particle size 

 (sieve-set 

 DIN 1171) 

 Pore volume 

 Adhering water 

 (water capacity^ 

 Permeability 

 for water 

 Water-content 



Alluvial sand with 96% 

 quartz, 2% feldspar, 1% 

 hornblende, 0.5% garnet, 

 0.2% mica 



1.0-0.2 mm fine sand; 

 rounded grains, 90% 

 between 0.3 & 0.6 mm. 

 36 Vol. % 

 11.7 Vol. % 



23.3 Vol. % 



0.4 Vol. % 



Chiefly quartz 



Edged grains 

 0.2-0.1 mm. 

 ("Schluflf") 

 41 Vol. % 

 22.3 Vol. % 



18.7 Vol. % 



0.4 Vol. % 



ment, size of cells,— was in general discernible (Table 2) but 

 not sufficient to understand all the phenomena. Besides, there 

 was the influence of the medium (seawater, fresh water), and 

 there were specific unknown qualities of single species of mi- 

 crobes, e.g., in the behaviour of Serrafia marcescens, which need 

 further investigation. 



Micrococcus B/lc had the highest degree of transmigration 

 with 91 and 97 per cent cells /ml of the suspension recovered after 

 eight days under limnic conditions and 65 and 96 per cent under 

 marine conditions (Table 2); during the second period of the 

 experiment, (washing out with sterile water) the number of 

 cells/ml of dropping water were in general the highest. Also 

 with Nocardia, the transmigration was high even though the rods 

 were big. The coccoidal cells migrated the fastest. The big rods 

 of B. mycoides were restrained nearly completely and only a 

 small number of cells appeared in the dropping water after 

 thirty minutes in fresh water and seasand. 



Transmigration was lower in seawater than in fresh water. 

 This may be due to an influence of the salt content of the water 

 upon the sediment and upon the surface conditions of the bac- 

 terial cells. The difference between fresh water and seawater 



