Micro-organisms of M apu: Sap 377 



The color was u>. flavor 4, and score 525; depreciation from 

 control, color 6, flavor 3, and score 400. 



81. Number 81 was a control heated to boiling and left in 

 the incubator without inoculation. It developed 3,250,000 colo- 

 nies per cc, typical of the subtilis group. The reaction was m', 

 N/100 acid. The sirup contained 89.23% sucrose and 7.51s 

 invert sugar. The color was 7, flavor 4, and score 600 ; deprecia- 

 tion from control (number 68), color 3, flavor 3, and score 325. 



It is evident that the sap used in the above series was 

 heavily contaminated by some spore-bearing organism which 

 apparently has the power of inverting sugar and which exercises 

 a further detrimental influence upon the flavor of sirup. Refer- 

 ence to the laboratory notes shows that after being heated the 

 samples were placed without being covered on the top of instead 

 of within the incubator to cool over night, in order that they 

 might be ready for inoculation the following morning; but 

 to prevent the entrance of falling dust a shelter of new clean 

 paper was supported a few inches above the tops of the buckets. 

 During the night there occurred a heavy wind storm. The 

 ground was partially bare and it is possible that spore laden dust 

 entered the laboratory through the rather large cracks which 

 had opened in the single layer of boards constituting the floor, 

 and that infection was produced in this way. Unfortunately the 

 infection was not suspected until the results of the bacteriological 

 and chemical analyses were known. Cultures of the organism 

 were not secured so that its identity is uncertain, but the agar 

 plate colonies were strikingly similar both in macroscopic and 

 microscopic appearance to those of Bacillus subtilis and spore 

 formation was apparent on unstained preparations from 4 days' 

 agar colonies. 



SUGAR AND SIRUP FROM SOUR SAP 



The inoculation work of the season was completed with the 

 preceding series, but a few experiments were made with natural 



sour sap. 



