G6 



ORGANOGRAniV. 



Fig. 159. 



Fig. 158 



Fig. ITiS. The Male Fein (Liistrwti /■ili.r-nni.i) Fig. l.W. A Tree-fern show- 

 ing u tutt of Jroncls iit tlie apex of ii lyiliidriLiil stem, which i« inlurgeU at iU 

 l>u»c, ra, by ti»c development of a iniuia of udventitious root*. 



the tliroe essential c)r;:;nns of the hij^lier ])laiits, namely a root, 

 .stem, and leaf. All plants, tioni the Mosses upwards, are 

 presented to us under ordinai-y eireuiustaiaes with u diotiuet 



