242 



OUTLINES OF PLANT LIFE. 



tissues of the leaves may be more compact. This reduces 

 transpiration by restricting the area of the air passages. 



Fig. 206. — Portion of a vertical section of a leaf of oleander, efi, epidermis of upper 

 face ; efo', same of lower face with stomata, j, in deep pits with numerous hairs, t ; 

 pal, palisade cells in two layers ; sy>, spongy cells ; h, h' , cells adapted to water stor- 

 age. Chloroplasts shown only in left-hand side of the figure. Magnified about 175 

 diam.— After Van Tieghem. 



B. Adaptations for taking up water. 



340. Absorption. — i. Some plants are adapted to imme- 

 diate absorption of moisture in the air or of liquid water 

 falling on their aerial parts. Such are, usually, the algse, 

 lichens, and mosses which grow in exposed situations. 2. 

 Certain of the higher plants are furnished with hairs adapted 

 to the prompt absorption of rain or dew, e. g. , Spanish moss. 



