341 1 



Bulletin 167 



NUMBER OL ORGANISMS IN SWEET MAPLE SAP 



Jn contrast to the figures in the preceding tahle the results 

 obtained from plating several samples of normal sap are of in- 

 terest. In some cases the sap to be analysed was gathered with 

 unusual care in order to secure as light an infection as might be 

 without special apparatus, while in other cases it was taken 

 from the commercial supply and is representative of the ordinary 

 sap of the orchard in which the work was done. These two 

 classes of material are grouped in separate columns. The higher 

 figures in the column headed "commercial sap'' were obtained 

 late in the season from material which was developing an un- 

 pleasant flavor and which clouded promptly when placed in 

 st< >rage for a few hours. In one of these cases (11) the count 

 obtained is higher than that from many of the sour saps reported 

 above, and in the other four (4, 5, 10, 12) it is very high. 



TABLE 2. ORGANISMS PER CC. IN SWEET MAPLE SAP 



No. 



Carefully collected sap 

 Nutrient Synthetic 



agar 



agar 



No. 



Commercial sap 



Nutrient Synthetic 



agar agar 



The influence of cleanliness upon the number of organisms 

 developing in maple sap may be seen in the results obtained in 

 the following experiments. 



Several trees were tapped with care, precautions being taken 

 to prevent the introduction of inert matter carrying micro- 



