2o6 



BACTERIOLOGICAL METHODS 



once gained access to the syrup they are not easily exterminated. 

 This emphasizes the importance of great care and cleanhness in 

 the preparation of all syrups. It is also a fact that high con- 

 centrates of sugar are not so liable to be attacked as are the 

 weaker solutions. The most favorable strength of sugar solution 



Fig. 68. — Bacillus californiensis isolated from the roots of the sugar beet. A 

 typical gum former found in the soil, on the roots and in the surface tissues of the 

 sugar beet and in the juice of the sugar beet, a, Beet root cells showing a mixture 

 of cell plasm and B. californiensis (mycoplasm); b, epidermal cells of the root show- 

 ing bacteria within the cell and also on the exterior; c, a bit of mycoplasm removed 

 from the cell by pressure; d, B. californiensis removed from the cells by pressure; 

 e, B. californiensis from a pure culture in beet root gelatin; /, zoogloea form of 

 B. col.; g, gelatinized form of B. col.; i, a single chain highly magnified (X 450 

 to 1000). 



is about 20 per cent. Development may, however, take place in 

 60 per cent, solutions. The organisms are facultatively anaerobic 

 and their growth is greatly accentuated by free aeration. Com- 

 pletely fining the containers will materially check and even 

 completely prevent the growth of the bacteria. 



