ELEMENTARY STRUCTURE. 



47 



Fig. 92. 



Fig. 93. 



Fig. 94. 





Fig. 92. Epidermal tissue from the leaf of the Iris (Iris germanica). p, p. 



Cuticle, s, s. Stomata. e.e. Epidermal cells. After Jussieu. Fig. 93. 



Epidermis of the Maize, a, a. Stomata. b, b. Zigzag reticulations 



formed by the sides of the cells. Fig. 94. Sinuous epidermis with 



stomata, from the garden Balsam. 



the epidermal cells are generally much thickened by layers of 

 secondary deposits, which gradually become thinner, and termi- 

 nate on the side walls (Jig. 98). This thickening of the upper 



^'i_A. 



Fig. 95. 





Fig. 95. Vertical section of the leaf of the Maize, showing the epidermis, a, a, 

 formed of one row of cells, with projecting hairs, g, g. 



Fig. 96. 



Fig. 97. 



Fig. 96. Section through the leaf of a Banksia. a, a. Epidermis with two 

 rows of colls, c. Spongiform parencli.vma. b. Hairs which are contained 

 in little depressions on the under surface of the leaf. After Schleiden. 



Fig. 97. Section through the leaf of Oleander, showing the epidermis com- 

 posed of three layers of thick-sided cells, and placed above a compact 

 parenchyma of vertical cells. After Brongniart, 



