MAPLE SAP AND SUGAR 169 
Before the Indians, there were many animals that had dis- 
covered the springtime sugar supply of the maple trees: sap- 
suckers, that tap the trunks in the neatest 
and most methodical and least injurious 
way imaginable (fig. 65); and porcupines, 
that strip the bark disastrously from young 
trees, killing them outright; and red 
squirrels, that.gnaw little basins in the 
upper surface of horizontal boughs and, 
when these fill with the sap, come to the 
Fic. 65. A sap-sucker basins for a soft drink (fig. 66). And 
ag es hand when these larger creatures set the sap 
Hons: flowing, there are innumerable lesser 
creatures, mostly flies and beetles, that come in swarms to 
be partakers with them. 
This store of sweets is the accumulated food reserve of the 
preceding season. It is stored as starch when the leaves are 
active, to be transformed into sugar and dissolved in the 
sap in early spring. When, at the approach of warmer 
weather in February and March, the days are warm and 
bright and the nights clear and frosty, changes of pressure 
in the vessels of the trees, due to the great diurnal changes 
of temperature, 
set the sap flow- 
ing. 
The warm 
sunshine on the 
treetops ex- 
pand the air in 
the trunks and 
increases the 
internal pres- 
sure so that 
from an y incis a be ( a mene drinking sap as it exudes from a maple 
me oug! er Cram). 
