FOLIAGE leaves: THE LIGHT- RELATION. 



27 



leaves (see Figs. 19, 2;3). In the case of ordinary shade trees 

 every direction of branch may be found, and the resvilting 

 adjustment of leaves noted (see Fig. 20). 



Looking up into a tree in full foliage, it will be noticed 

 that the horizontal branches are comparatively bare be- 



FiB. 22. A mosaic of fern (^AdmntwnC) leaflets. 



neath, while the leaf blades have been carried to the upper 

 side and have assumed a mosaic arrangement. 



Si)rays of maidenhair fern (see Fig. 22) show a remark- 

 able amount of adjustment of the leaflets to the light side. 

 Another group of fern-plants, known as club-mosses, has 

 horizontal stems clothed with numerous very small leaves. 

 These leaves may be seen taking advantage of all the space 

 on the lighted side (see Fig. 21), 



