EXPERIMENT STATION BULLETINS. 451 



both aerobically and anaerobically (under sterile paraffin) at 25°, 37° and 55°. 

 Enrichment cultures were also made in sterile pork infusion (meat piece me- 

 dium) for isolation of B. hotulinus should it be present. These latter cultures 

 proved negative. 



At the same time two guinea pigs weighing about 275 grams each were fed 

 directly by means of a pipette with 0.5 c. c. of the string bean liquor to see if 

 it was toxic. 



RESULTS OF EXPERIMENTS 



Two types of colonies were found on the aerobic string bean agar plates at 

 25°. Transfers from each type were made to sterile tubes of string beans and 

 incubated at this temperature both aerobically and under sterile paraffin oil. 

 Visible growth was obtained aerobically but not under oil. This suggested 

 that the types of bacteria isolated were not the cause of the decomposition 

 in the can of the string beans because the organisms in the can were anaerobic 

 or facultative as to their air requirements. This was not considered as con- 

 clusive evidence, however. No colonies were found on the aerobic plates at 

 37° or 55° nor on the anaerobic plates at room temperature and 37°C. At 55°, 

 however, gas bubbles were formed extensively underneath the paraffin which 

 was liquid at this temperature. Eight days after inoculation when the 

 paraffin was removed from the 55° plates no visible colonies could be seen on 

 the first two dilution plates; on the third plate a yellowish mass about 1 mm. 

 in diameter but not resembling a colony was present which on examination 

 under the microscope appeared to contain bacteria, confirmed by a hanging 

 drop. 



Shake cultures (designated as Str. BIC) were made from this colony in 

 gelatin agar —1.0 and kept at room temperature; both aerobic and anaerobic 

 shakes were made in corn agar, starch agar, and in string beans, incubating 

 the last named cultures at 55°. In 15 hours gas production was noted in the 

 starch agar shake, but not in the other two media. (See table 1.) 



About this time, eight days after the first cultures and feeding experi- 

 ments were made, one of the guinea pigs died, and all cultures from the con- 

 tents of the stomach, small and large intestines, and from the heart blood, 

 when grown at 55° in starch agar showed the same gas formation. Two 

 days after this a small loopful of the heart blood drawn aseptically from the 

 other guinea pig was cultured in starch agar at 55° with the same result. 

 The thermophile was thus found to be living and evidently growing in the 

 blood stream of the guinea pig with no apparent harm to the animal. About 

 a month later cultures were made from large quantities of the heart blood of 

 the living guinea pig with negative results. The pig seemed to have sur- 

 vived the temporary bacteremia (?) with no harmful results. Barlow found 

 that no toxic effects on man were apparent after swallowing three teaspoon- 

 fuls of corn spoiled by a thermophile and concludes that "apparently its 

 growth at high temperatures in canned corn does not result in the production 

 of toxins." He also states that, ''This thermophilic organism does not 

 grow at temperatures as low as the blood temperature of mammals," but 

 cites no experiments to prove this statement. 



In the meantime, in spite of the fact that active gas production continued to 

 occur in the starch agar shakes of the organism, Str. BIC, no colonies appeared. 

 Transfers were made from the starch agar shake showing continual active 



