1. Transverse section of leaf of Verbena ciliata. The substomatal spaces below stomata of upper 



surface may readily be seen. 



Figs. 2-7. Stomata of Verbena ciliata in air deprived of carbon dioxid. 



2. Normal condition at 6^30™ a. m. Fixed with absolute alcohol. No oil is visible. The starch 



content may be seen in fig. 3. 



3. Normal starch content at 6 h 30 m a. m. Stained with iodine after boiling. 



4. Normal condition at 11 a. m. Fixed with absolute alcohol. Oil drops may be seen. The starch 



content may be seen in fig. 5. 



5. Normal starch content at 11 a. m. Stained with iodine after boiling. 



6. Stoma in air deprived of carbon dioxid at 11 a. m. Fixed with absolute alcohol. Compare 



with fig. 4. Oil drops are present. The starch content is small, as is seen in fig. 7. 



7. Stoma in air deprived of carbon dioxid at 11 a.m. Boiled, and then stained with iodine 



The plastids are small. 



