STRUCTURE 



439 



The latter organs are, quite exceptionally among the higher 

 plants, wholly absent. 



'I'hc stem t-nrls flist;ill\- in a terminal bud (f. M). the 



f.1.3 



fl-* J-. 1.1 



Z.li 



f.l.i' 



\r(% 



f.la 



I liftii' 



'■' S.I.S 



s.l.% 



Fig. 114. — Distal portion of a Salvinia plant seen obliquely from 

 l)clow. 



The stem (st) ends in a terminal bud (t. M), and the part figured 

 contains three nodes, each bearing a pair of foliage-leaves (/ /. 1-3, 

 /. /. i'-3'), and a much-divided root-like submerged leaf (.r. /. 1-3). 

 On the bases of the submerged leaves are borne groups of sori (so), 

 containing sporangia. (Slightly enlarged.) 



(From Vines, after .Sachs.) 



growing point of which is formed by a two-sided apical cell : 

 it is traversed by a single vascular bundle, which sends 

 branches into the leaves. 



