BIOLOGY OP CLOSTRIDIUM WELCHII 



397 



TABLE 3 

 Summary of source of principal subgroups 



b. Frequency curves. Using the results obtained from a 

 study of the 56 strains used in this classification, frequency 

 curves were plotted for the carbohydrates, glucose, galactose, 

 maltose, lactose, sucrose, starch, inulin, glycerol and dextrin 

 and liver. 



The curves show an entirely irregular variability without any 

 particular significance. 



X. THERMAL DEATH POINT 



1 . Method. The thermal death point of strains of Clostridium 

 Welchii was determined both in the vegetative and spore stage 

 according to the procedure in Standard Methods for Water 

 Analysis, 1912, except that five loopfuls of the culture were used 

 instead of three in order to overcome the influence of the film 

 of oil and insure inoculation of the organism. Cultures were 

 plated at least twice to insure their purity and if on microscopical 

 examination any contamination was present, plating was repeated 

 until a pure culture was obtained. The pure cultures were grown 

 in glucose-liver broth for twenty-four hours and then transferred 

 to fresh glucose-liver broth and grown for another twenty-four 

 hours. 



The sources from which Clostridium Welchii was isolated to 

 study thermal death point were market milk, human feces, cow 

 feces, and horse feces. In the case of the cultures of market 

 milk, some had been subjected to artificial cultivation for four 

 months, others for three months, and still others for two weeks 

 before testing their thermal death point while the cultures from 



