FLOKAL SYMMETRY, ETC. 



123 



To study leaf arrangement, get straight leafy 

 stems, or shoots, a foot or more in length, such as 

 are shown in Figs. 268 and 269, from any vigorous 

 tree, shrub, or herb. First separate the specimens 

 having opposite and verticillate leaves from those 

 with alternate leaves. 



FIG. 269. 



Observe that the successive pairs of leaves in op- 

 posite-leaved plants are placed at right angles to each 



