74 AGR<>N>MY 



leaf and the outer air, therefore, the epidermis contains great 

 multitudes of tiny openings called atomata (singular, stoma), 

 which connect with the intercellular spaces. Each stoma 



FIG. 61. Epidermal cells and stomata from the leaf of the begonia, a 

 dicotyledon. (Much enlarged) 



is provided with a pair of guard cells roughly semicircular 

 in shape, which can, upon occasion, enlarge or dimmish the 

 size of the opening. The stomata are exceedingly minute, 



