VERBENA CILIATA. 

 Table 4. — Mobility of stomata. 



'3 



Table 5. — Changes in dimensions of stomata irrigated with water after remaining some 



months in absolute alcohol. 



Table 6. — Measurements of three freshly taken stomata, open in water and closed, partly 

 or nearly, by iodine (Verbena ciliata). 



It will be apparent from the foregoing brief description of the two plants 

 chiefly concerned in the pages to follow that they offer decided advantages 

 for a preliminary study of physiology of the stomata in desert plants. 



The ocotillo is a highly specialized spinose type, producing normally at 

 least two complements of leaves annually; these are certainly no more 

 specialized anatomically than those of, say, Lactuca scariola. The verbena 

 is a successful herbaceous desert plant with leaves of no more specialized 

 anatomical characters than those of numerous mesophytes, as, e. g., Raphanus. 



In point of size, the stomata of both plants are approximately of the aver- 

 age size, and their numbers per unit of area are not reduced. 



In both plants the stomata are of a simple type and have no accessory 



