MICHIGAN ACADEMY OF SCIENCE. 
253 
rather too small, since the cooler leaf masses collected a considerable 
amount of moisture in the fog which arose frequently during the 
night. This condensed moisture ran largely into the tanks, thus making 
the reading indicated too small, while some remained several hours 
on the plant surfaces before it was evaporated, thus retarding transpira- 
tion from the wetted parts. 
The results so far obtained are but preliminary, and, while complete 
in themselves, they are in no respect final. Sufficient data are at hand 
to make further deductions, and these will be included in a later paper. 
Ann Arbor, Mich., April 3d, 1911. 
