M [< R0 ORGANISMS "1 M \n.i-. SAP 



the leaf buds are ready to open. It is popularly believed thai 



the swelling of the buds, associated with the renewal of vegeta- 

 tive activity in the tissues of the tree, is accompanied by a 

 change in the composition of the sap within the trunk ; and that 

 the alteration in color and flavor are manifestations of this 

 change. The term 'buddy' is universally used to descrihe this 

 sort of sap." (See Plate V). 



"The sirup made from late runs is much inferior to that 

 derived from the earlier flows. 'Last run' goods are often 

 very dark in color and usually lack the delicate flavor possessed 

 by the hest sirups. Moreover, the quality of sirup varies 

 markedly from year to year and these variations are seldom local 

 in distribution. Such widespread fluctuations in quality are not 

 accidental but of necessity must be associated with some funda- 

 mental cause or causes. It is conceivable that they may be re- 

 lated to weather conditions, either during the preceding summer 

 or during the progress of the sugar season. It is known, more- 

 over, that inferior products result from carelessness and lack 

 of cleanliness in collecting and handling maple sap. Such pro- 

 cedures must occasion a great increase in the bacterial content 

 of the sap, just as in dairying they entail serious bacterial con- 

 tamination in milk. The proteid, carbohydrate and mineral con- 

 tents of maple sap are sufficient to make it a fairly good medium 

 for the development of bacterial life, provided suitable tempera- 

 ture relations are maintained ; and the vital activities of large 

 numbers of micro-organisms would presumably affect the flavor 

 and quality of the sirup produced under such conditions." 



"Reflection upon these facts strongly suggests the pos- 

 sibility that micro-organisms may be associated with the inferi- 

 ority of the maple output in all the cases cited, or that, indeed, 

 they may be the direct cause of the troubles. Inevitably they 

 must be present in the sap and it is to be expected that they 

 would be more abundant toward the close of the sugar season 

 than earlier, because the warmer weather would favor their in- 

 creasingly rapid development and multiplication. It is conceiv- 



