50 Principles of Plant Culture. 



65. Stomata (stom'-a-ta). Minute openings through 

 the epidermis occur in the leaves and young stems of 



land plants, 

 connecting 

 intercellular 

 spaces (I, 

 Fig. 17) with 

 the external 

 air. These 

 openings are 

 each bounded 

 by a pair of 

 g u a r d-cells, 

 called stom- 



FIG. 18. Showing stomata (st.) on leaf of the ata (singU- 

 garden beet. Moderately magnified. (After Frank 

 and Tschirch). See also Figs. 15, 19 and 22. Jaj* S t m a 



(sto'-ma), Figs. 18 and 19, St). They are chiefly found 

 on the lower side of leaves, and are extremely numer- 

 ous, but are too small 

 to be seen without the *p ^J} 

 microscope. An aver- 

 age apple leaf has 

 been computed to 

 contain about 150,000 

 stomata to the square 

 inch on its lower 

 surface. These cells, 

 which are attached 

 together only at their ends and are thickened on their 

 inner side, become bent or crescent-shaped when turgid, 



FIG. 19. Showing tomato (st.) on leaf 

 Oldenburgh apple. Highly magnified. 



