68 THE VEGETATIVE FUNCTIONS OF PLANTS 



thawing and freezing. During this season, in many parts 

 of the country, it is customary to ''tap" the trees, by 

 boring a small hole into the trunk far enough to enter the 

 wood, and then insert a wooden or metal "spiggot" or 

 spout, through which the sap flows out and is caught in 

 pails. It is then ''boiled down," either in the sugar bush 

 or in the house, until the water has passed off in large 

 quantities as steam, leaving a thickened maple syrup in 

 the kettle or evaporating pan. If the boiling is continued 

 the syrup, when cooled, becomes maple sugar. The saps 

 of the sugar-cane and of the sugar-beet are, as is well 

 known, the source of the ordinary sugars of commerce. 



