IKj^Oi.MJTYLEiKjXS AND DlCi iTYLEDU>;S 233 



margin of the leaf, but forms a " closed Tenation," so that 

 the leaves usually have an even {entire) margin. There 



are some notable exceptions 

 to this character. 



(4) Cyclic flowers trim- 

 erous. The "three-parted"' 



Fig. 215. Two types of leaf venation; the figure to the left is from Solomon's seal, 

 a Monocotj'ledon, and shows the principal veins parallel, the very minute cross 

 velnlets being invisible to the naked eye; that to the right is from a willow, a 

 Dicotyledon, and shows netted veins, the main ccntnil vein (midrib) sending out 

 a series of parallel branches, which are connected with one another by a network 

 of veinlets. — After Ettingshausen. 



flowers of cyclic Monocotyledons are quite characteristic, 

 but there are some trimerous Dicotyledons. 



Bicofi/h'dnns. — (1) Embryo with lateral cotyledons and 

 terminal stem-tip. 



{2) Vasciilar bundles of stem forming a hollow cylinder 

 (Fig. 216, w). This means an annual increase in the diam- 



