EXPERIMENT STATION BULLETINS. 475 



If we consider a "flat sour" to be an apparently normal can, the contents 

 of which have a hydrogen-ion concentration above 5.8* without the pro- 

 production of any gas, or of only a very small quantity, it will be noticed 

 from Table IV that no flat sours were developed in the cans incubated at 55°C. 



I B String Beans, having pH of 5.8 was a springer, therefore cannot be 

 considered as a flat sour. Other inoculated cans in this set having a pH 

 as high as 5.8 were either tight swell or apparently normal. 



In Table V we find that I A, Lima Beans; I A, Corn; I A, Peas; I A, Pump- 

 kin; I B, String Beans; I B, Peas; I B, Tomatoes; VI B, String Beans; VI B, 

 Corn; VII B, String Beans, and VII B, Tomatoes, all have a hydrogen-ion 

 concentration of 5.8 or above, and all except tomatoes may be considered as 

 being flat sours. The unopened tomato control has a pH of 5.6, therefore the 

 inoculated tomatoes mentioned above could not be considered flat sours. 



Organisms I A and VII B both apparently produced flat sours mcorn, 

 while I A and I B both apparently produced flat sours in peas, and VI B and 

 VII B in string beans incubated at 37°C. 



From Table VI it will be noticed that all four organisms produced the 

 greater number of flat sours at 20°C. By subsequent test thermophiles 

 developed. 



It is quite evident from Table IV that nothing but thermophiles devel- 

 oped in the cans incubated at 55°C. The cultures in many of these cans con- 

 tained a thermophile resembling Str. B I C, an anerobic thermophilic organism 

 isolated from string beans described in Part I, page 6. They showed gas and 

 a few almost invisible colonies, producing minute gas bubbles and referred 

 to by Z. N. W. as "ghost" colonies. 



It is very doubtful whether any of the organisms developing in the cultures 

 kept at 65°C were those placed in the 55° cans, since the incubating tem- 

 perature employed was 10 degrees higher than the storage temperature of the 

 cans. 



One of the writers (Z. N. W.) believes that the thermophiles developing in 

 the cultures were already in the cans when incubated since no preliminary 

 incubation of the cans was made. 



*i. e., pH reading below 5.8. 



