I2J: 



PLANT LIFE. 



157. Special forms. — Foliage leaves may be modified to 

 serve special purposes witliout wholly losing their function as 



Fig. 152 —Palmately veined and branched leal ot N orway maple. About half natural 

 size. — After Kerner. 



foliage. For example, the petiole may be made sensitive to 

 contact and adajited to wrap about slender objects, like a 

 tendril, as in clematis and 

 nasturtium (fig. 154). Such 

 jilants are called leaf-climb- 

 ers. 



Fh.. 153. 



F"'iG. 153, — Pinnately \eined leaf of buckthorn, with looped ribs forming a seh'edge. — 

 After Kerner. 



Fit;. 154. — Portion of a [)lant of the dwarf garden-nasturtium {Tyo/^cpolii ni minus). 

 The long petiole .:, u, u of the leaf / is sensiti\'e to contact and has coiled about 

 the support and its ^luii stem, .W . :;, axillary bi"anch. Natural size. — ^Vfter Saclls. 



