EXPERIMENT STATION BULLETINS. 455 



Several days later the cultures marked with a negative sign also showed 

 gas production, so 100 per cent of the cultures tested remained viable. 



Tliis interesting thermophile is a straight rod, motility not observed, 

 single, in pairs and short chains; Gram negative, spores terminal or subter- 

 minal. In different media and at different stages of growth, "nodules" or 

 enlargements are seen on the rods, it being impossible to determine whether 

 they are located in any one place on the cell and whether a rod has more 

 than one of them. Again, beaded forms are present, or masses containing 

 small, deeply stained granules are seen which resemble very much the syn- 

 plastic stage described by Lohnis. 



Barlow's thermophiles from canned corn incubated at 60° and 70°C. 

 were "gram negative, slender rods, single or united in two's, or in short and 

 long threads." In practically every apparently sound can which swelled 

 after incubation at 60° to 70°, this type of organism was the only type pres- 

 ent in numbers sufficient to cause spoilage. Barlow observed neither spore 

 formation nor motility in the organism described. 



Experiments have not been performed to determine the maximum, mini- 

 mum and optimum temperatures for Str. BIC but from observations during 

 the course of its incubation the minimum of rapid groAvth is between 40° and 

 50°, the optimum from 55° to 65°; it is not killed by a temperature as high as 

 70°, the temperature at which the incubator was found one morning. 



From the food standpoint this organism is important because it develops 

 so rapidty and produces gas at high temperatures which would be inhibitive 

 to common bacteria. In the canned beans from which it was isolated after 

 the cans were processed (23^ hours only), the flame was turned off from be- 

 neath the wash boiler in which the cans were being heated and the cans left 

 in the hot water until both the water and the cans with their contents were 

 cool, which took several hours. 



There is evidence, however, that this organism can grow at lower temper- 

 atures under certain conditions than 55° because of its invasion of, and mul- 

 tiplication in the blood stream of the guinea pig and also because of the large 

 quantity of sediment found in the cans. In the latter case the growth must 

 have proceeded very slowly indeed after the contents of the can had cooled 

 to room temperature. This accounted for the failure of the organism to 

 produce swells or leaks, or both, or to burst the cans. 



In Part II of this bulletin mention is made of finding a similar organism 

 in inoculated cans incubated at 55°. 



The cans were submerged in water and the water kept at 55°, Along with 

 these cans were kept unopened checks of each type of food. The examina- 



