324 



PLANT LIFE. 



moss. 3. < Uhcr plants adapt aerial routs to the absorption of 



moisture from the air, as well as falling water. (See ^ 196.) 

 4. Many are surrounded by the bases of dead leaves, which 

 act as a sponge for absorbing water, and supply it gradually 

 to the stem or younger leaves. Living leaves, sometimes 

 singly, sometimes in clusters, form cuplike or tubular struc- 





Fk;. 368.— Portion of a vertical section of leaf of oleander. <■/, epidermis of upper 

 face; e/>' , same of lower face with stomata, s, in deep pits with numerous hairs, t: 

 pal, palisade parenchyma in two layers; ,r/, spongy parenchyma; //, /;', hypoderma 

 adapted to water storage. Chloroplasts shown only in left-hand side of figure. 

 Magnified about 175 diani. — After Van Tieghem. 



tures, acting as water receptacles, from which it can be 

 absorbed as required. Such adaptations occur chiefly in 

 epiphytes. (See" 454-) 5- Many xerophytes develop ex- 

 ceedingly long tap roots, which penetrate the soil deeply 

 to a permanent water supply. 



