100 PHARMACEUTICAL BACTERIOLOGY. 



very destructive to crop plants, causing diseases of roots and other plant 

 organs. Bacillus calif orniensis, isolated from sugar beets and from sugar 

 beet soil, appears to promote the growth of sugar beets, particularly the 

 seedlings. The microbic leguminous fertilizer of the Department of Agri- 

 culture, Washington, D. C., is a slight modification of the Hiltner method. 

 The microbic cultures are grown in the absence of nitrogen or nitrogenous 

 compound making them nitrogen hungry, thus increasing their potency to 

 produce nodules when brought in association with germinating leguminous 

 plants. The process is patented in the United States, and free samples have 

 been liberally distributed among farmers for test purposes, but the results 

 reported have been rather variable, and as a whole quite unsatisfactory. 

 The indications are, however, that future experiments will clear up the pres- 

 ent difficulties, and some of these so-called vest-pocket microbic fertilizers 

 will no doubt prove highly beneficial. 



2. Bacteria in Milk and in the Dairying Industry. 



Bacteria play an important part in modern dairying, and they are destined 

 to play even a more significant part in the near future. Certain microbes 



FIG. 52. Lactic acid bacillus. There is a large group of bacteria, similar in appear- 

 ance to the lactic acid bacillus, which have the power of forming lactic acid in milk. Some 

 of these are used in pure culture to make the so-called artificial buttermilk. Milk bacte- 

 riology is still in its infancy. For so long have we been accustomed to the use of contami- 

 nated (filthy) milk that in a recent test made with samples of pure milk and samples of which 

 cow manure was added, 90 per cent, of those who were asked to taste the milks preferred 

 the milk to which the cow manure was added, declaring that it was the only sample which 

 had a "milk flavor." 



are active in the ripening of cream, butter and cheese. Formerly it was 

 customary to let nature attend to the inoculation of the cheese, resulting 

 in a rather variable product. Now the up-to-date dairy-man inoculates the 



