Jan., I92ij WIGGANS — OSMOTIC CONCENTRATIONS OF GUARD CELLS 
39 
employed in the experiments, (2) to the greater amount of sunshine at 
Columbia, and (3) to the greater temperature and humidity of the green- 
house in which the work was carried on at Columbia. There was never a 
time when the stomata were found completely closed at Columbia; most of 
the time they were found wide open. (On account of the equipment at 
Columbia it was impossible to determine the condition of the stomata 
at night.) 
g'A/wN. /Ofyiri' JiPrt\ ^P.iv^. 
Fig. 7. Young beets. Observations made at Columbia. 
Table 3 
Osmotic Concentration Expressed in Atmospheric Pressure 
Ithaca, New York 
Columbia, Missouri 
Epidermis 
Guard Cells 
Epidermis 
Guard Cells 
Zehrina pendula 
Cyclamen 
Iresine 
Beets 
5-35 
9.48 
11.33 
. 11.32 
12.55 
I8.II 
10.09 
11.63 
12.55 
29.49 
39-52 
31.50 
