lOY/A ACADEMY OF SCIENCE 
15 
Along the same line, Piscli evaporimeter readings were taken at two 
stations in the plant house : I. beside a geranium exposed all round 
to light and air, and II. suspended among the branches of the densely 
crowded plants, about 2 feet distant. The evaporimeter readings for 
six days being as follows: 
Station I. 4.7 hundredths of cu. in., 7.5, 11.0, 14, 17.5, 20. 
Station II. 4.5, 5.0, 7.0, 7.2, 9.2, 10. 
Stomata were examined from leaves near the two instruments, and 
the same difference noted above appeared, i. e., the leaves on the plant 
in the exposed situation showed large guard cells and stomata more 
widely distended, those from the crowded one showed many and small 
guard cells. 
