Micro-organisms oi? Maple Sac H3 



127 and 130) were made from sour sap drawn very late in the 

 season, so that it was not only sour but buddy. The three re- 

 maining samples (Nos. 22, 23 and 25), however, were made from 

 sour sap free from buddy flavor. Samples 22 and 25 were con 

 centrated to sirup the same day they flowed, and at the time of 

 evaporation the first drops to run had not hcen out of the \ 

 cular tissue more than twelve hours. Sample 23 was evaporated 

 thirty-six hours after it began to run. These sirups might he ex- 

 pected to be at least as good as the ordinary material made from 

 sour sap and probably superior to it. They are therefore used in 

 the following comparison of depreciation values, which values in 

 these cases are calculated from the average of all controls of the 

 three seasons, instead of from the average of first run controls. 

 The average color was 12, flavor 3, and score 600; average de- 

 preciation from all controls, color 8.2, flavor 1.6, and score 311. 



DISCUSSION OF DEPRECIATION VALUES 



The specific influence of the various groups of organisms 

 and of natural souring upon sirup is seen most clearly from a 

 study of the depreciation values. If the groups are arranged ac- 

 cording to the average amounts of depreciation in color they fall 

 into the following order : 



A glance at the foot of the table shows that the sirups mosl 

 seriously injured in color were made from sap souring naturally. 



