195 



order to admit ilie air. Now llie covej- of the peiri dish is easily 

 removed. 



The number of anaerobes was counted in the same way as that 

 of the aerobes in the same sample. 



Because we had determined the specific weight of the soil-samples, 

 we could establish the number of germs per cc. 



Our results we have tabulated on page 7. 



The time in which the anaerobes yielded a constant number of 

 colonies was considerably longer than that of the aerobes. 



It strikes us Ihat the anaerobic test yields a total of germs which 

 is much greater than that of the aerobic one, while the amount of germs 

 in B 28 and B 31 is much higher than that of B 29. The last- 

 named fact is perhaps due to the higher content of organic matter 

 in the first two soil-samples. 



For the sake of comparison we may add that in raw water from 

 the dunes the number of bacteria per cc. varies in round numbers 

 from 400 to 1800. 



^ 6. It appears that microhes derived from aerobic and anaerobic 

 cultivation belong for the greater part to the facultative anaerobes. 



The number of species of bacteria obtained in the preceding para- 

 graph by the method described, appeared to be only small when 

 we examined their qualities. Generally the anaerobes and the aerobes ^) 

 were not identical. The following table shows the number of species 

 of microbes we found : 



As to their properties aerobes revealed some resemblance in 

 acidformation from glucose, Berlin-blue formation from ferri-ferri- 

 cyanid, the formation of hydrogen-sulphid from broth (lead-carbonate 

 test), the splitting of aesculin, the formation of katalase, and most 

 often in the inability to ferment glucose, to form lipase and diastase. 

 Spores were not formed. 



1) Probably B 29 anaerobe and one of the species B 29 aerobe were identic. 



