Micro-organisms of Maple Sap 





washed before being" hung on the trees. That the crevices and 

 interstices of the wood afforded ample lodging places for micro- 

 organisms is readily seen from the fact that 6,500,000 colonies 

 per cc. developed from the mixture of sap obtained, and only a 

 few of them were characteristic of the organism from tree 3 

 (Plate VII). The reaction was 5.5% N/100 acid. The sirup 

 contained 88.25% sucrose and 6.21% invert sugar. The color 

 was 9, flavor 4, and score 550; depreciation from control (number 

 66), color 6, flavor 3, and score 400. 



series 8: sirups 68 to 73 



The sap of this series ran on March 22, and was collected 

 in the evening and stored over night in buckets, at a tempera- 

 ture slightly above its freezing point. The following morning the 

 samples were thoroughly mixed, and all but one were heated 

 to boiling and allowed to cool in water. At 3 p. m., they were 

 placed in the incubator and inoculated. The temperature main- 

 tained during the three days' incubation period may be seen by 

 reference to the graph (figure 9). 



to 



ts 



(0 

 J5 



r' 



Fig. 9. Graph of incubation temperatures for series 8 ; saps 68 to 73 in- 

 clusive. The arrow heads on next to the bottom line from left to right indi- 

 cate respectively the time of inoculation, the time of evaporation of the first 

 sample and the time of evaporation of the last sample. 



68. Number 68 was a control boiled down on the morning 

 of March 23. Just before evaporation it contained 500 organ- 

 isms per cc. The reaction was 2.5% N/100 acid. The sirup 

 contained 96.90% sucrose and 0.51% invert sugar. The color 

 was 4, flavor I, and score 925. 



69. Number 69 was inoculated with fluorescent organism 

 CLIV. It was recovered in practically pure culture from the 

 green sour sap which resulted. The plates showed a count of 



