Micro-organisms oi? M.\ri.r Sac 357 



sucrose and 1.58% invert sugar. The color was 6, flavor 1, 



and score 875. 



SIRUPS PROM LAST RUN SAP IN I909 



No more inoculation work was conducted during the season 

 of 1909, but several samples of sirup were made with a view 

 of determining - the possible influence of physiological changes 

 in the tree upon the quality of sirup. As previously stated, 

 trees were selected for this purpose which were "running sour," 

 that is to say trees from which clear sap was no longer being 

 obtained. The spouts usually "dry up" or cease to run quite 

 promptly after the appearance of this phenomenon. The aim 

 was to wait till the last day a tree was likely to run before making 

 the experiment. A fresh tap from which the sap flowed clear 

 was then made about 4 inches to one side of the old one. The 

 two types of sap thus secured from the same tree at the same 

 time would presumably be very similar in character until they 

 left the vascular tissues. That from the old taphole, however, 

 becomes very heavily infected as it flows from the spout while 

 the other is relatively free from infection. Any difference in 

 quality of the two sirups obtained under such circumstances 

 would seem to be attributable to the influence of micro-organ- 

 isms, while any differences in quality between controls of the 

 first runs, and the last run material from the fresh taps, would 

 reasonably be ascribed to physiological changes which had taken 

 place within the tree. 



21. Number 21 was made from sweet sap obtained by re- 

 tapping the first sour tree observed during the season. This 

 was drawn on April 12. The sirup contained 95.19% sucrose 

 and 0.82% invert sugar. The color was 3, flavor 1, and score 

 950. The color was 3 grades superior to the first run control 

 of the season, the flavor equal, and the total score 75 points 

 higher. 



22. Number 22 was made from sour sap obtained from the 

 same tree at the same time as the sap for 21. The sap was 



