igig] 



WEAVER &- MOGENSEN— TRANSPIRATION 



415 



Acer saccharinum 



Weighings of a battery of 1 2 soft maples were made on the same 

 dates as those for the elms. The containers were of the same size, 



Fig. 15. — Mean temperature (solid line) and mean humidity (broken line) during 

 several intervals from September 20 to October 26, 191 7. 



Fig. 16. — Average daily losses in grams from seven i-year-old maple trees; Sep- 

 tember 20 to November 2, 191 7. 



and the batteries and the methods of handling them were so similar 

 throughout that further description will be unnecessary. 



