LABORATORY AND GREENHOUSE STUDIES. 87 



(G) Cultures in medium 4229, neutral beef bouillon plus 1 per cent 

 dextrose, after 48 hours at 37° C. The number of cubic centimeters 

 of Fehling's solution reduced b}^ 10 centimeters of culture was as 

 follows : 



No. 6, 10; No. 1 a, 10; No. 5, 10; No. 1, 10; No. 4 a, 11; No. 4, 5; 

 No. 3, 10; Bacillus coli, 10; check 2, 20; check 5, 10. 



The results in this experiment indicate that on an average one-half 

 of the sugar was exhausted in 48 hours. 



The experiments may be summarized as follows : 



Experiment 1: In 2 per cent dextrose after 55 days. 



Bacillus coli used one-third of the amount of sugar. 



Coconut used one-fifth of the amount of sugar. 

 Experiment 2: In 1 per cent dextrose after 5 days. 



Bacillus coli used two-twentieths to four-twentieths of the amount of sugar. 



Coconut used two-twentieths to three-twentieths of the amount of sugar. 

 Experiment 3: In 1 per cent dextrose after 47 days at 37° C. 



Bacillus coli used one-half of the amount of sugar. 



Coconut used one-half of the amount of sugar. 

 Experiment 4: In 2 per cent dextrose after 12 days. 



Bacillus coli not tested. 



Coconut (No. 5) used one-fourth of the amount of sugar. 

 Experiment 5: In 2 per cent dextrose after 23 days. 



Bacillus coli used one-half of the amount of sugar. 



Coconut used one-twentieth to one-third of the amount of sugar. 

 Experiment 6: In 1 per cent dextrose after 48 hours at 37° C. 



Bacillus coli used one-half of the amount of sugar. 



Coconut used one-half to three-foiu-ths of the amount of sugar. 



In these experiments the amounts given for coconut are the average 

 of the coconut organism series 1 to 6. The results indicate that from 

 small quantities up to one-half ' the amount of sugar in a 1 per cent 

 or 2 per cent solution of dextrose is broken up by the organism. In 

 experiment 6 the limit of coconut is given as three-fourths. Tliis 

 unusual amount may be due to error in the test, for it is difficult, 

 even with the utmost care, to ascertain the exact end of the reduction 

 in each case. In general, it seems safe to assume that any error lies 

 on the side of reckoning too much sugar used rather than too little. 

 It is a very easy matter to allow a Httle of the blue FeliUng to stand 

 unnoticed in the intense orange-red of the reduced solution. In these 

 experiments, however, it is shown that Bacillus coli and the coconut 

 organisms behave much alike in their relation to the sugar content 

 of the medium. 



1 Scruel, M. Contribution k 1' Etude de la Fermentation du Bacille Commun de I'Intestin." Archives 

 Mfidicales Beiges, ser. 4, vol. 1, 1893, pp. &-33, 83-107. 



M. Scruel records, for the amount of sugar consumed, the following: 1 day, 0.92 out of 3; 2 days, 1.22 out 

 of 3; 3 days, 1.25 out of 3; 6 days, 1.28 out of 3. And another time: 1 day, 0.50 out of 2; 2 days, 0.78 out of 

 2; 3 days, 0.81 out of 2; 4 days, 0.88 out of 2. 



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