324 Bulletin 167 



TABLE OF CONTENTS 



Part I. Micro-organisms Occurring in Maple Sap and their In- 

 fluence on the Color, Flavor and Chemical Composi- 

 tion of Sirup 333-418 



Introduction 333 



The relation of micro-organisms to spoiled maple sap 336 



The number of micro-organisms in maple sap 338 



Number of organisms in sour maple sap 339 



Table 1. Organisms per cc. in sour maple sap 339 



Number of organisms in sweet maple sap 340 



Table 2. Organisms per cc. in sweet maple sap 340 



Table 3. Organisms per cc. in sap obtained in sterilized 



containers 341 



Bacteria] content of sap obtained under septic conditions as 



compared with aseptic conditions 341 



Table 4. Organisms in sap from fresh and from sour tap- 

 holes 341 



Influence of tap-hole infection upon the flora of sap 342 



• Table 5. Organisms from tap-hole and spout per cc. of 



maple sap 342 



Influence of container on bacterial flora 343 



General plan of field experiments 343 



Method of sirup scoring : '>4~> 



Table 6. Amounts of ingredients to be used in preparing 



solutions for the color scale 348 



Table 7. Values assigned to color grades 349 



Table 8. Values assigned to flavor grades 349 



Inoculation experiments in 1909 349 



Detailed discussion of samples :;: >1 



Series 1: Sirups 1 to G 35] 



Series 2: Sirups 7 to 12 353 



Series 3 : Sirups 13 to 20 355 



Sirups from last run sap in 1909 357 



Inoculation experiments in 1910 359 



Series 4: Sirups 27 to 40 361 



Series 5: Sirups 41 to 48 3G5 



Series G: Sirups 49 to 37 



Series 7 : Sirups 58 to 65 370 



Influence of container upon quality of sirup 372 



Series 8 : Sirups G8 to 73 373 



Series 9: Sirups 74 to 81 75 



