SELAGINELLACEyE 



■4'3 



trie and closed. In the centre is the xylem, consisting chiefly of scalari- 

 form and reticulate tracheides ; this is completely surrounded by the 



Fig. 23. — Transverse section through leaf of 6". incequaV/olia. ch, chlorophyll-bodies ; co, 

 upper epiderm ; eit, lower epiderm ; j/, stomates ; /, -air-cavity surrounding vascular bundle 

 and traversed by trabecules. (After Goebel, magnified.) 



Fig, 24. — Transverse section of stem of 5". deniiculata Lk. ^, air-cavity 

 surrounding * vascular ' bundle. (After Goebel, magnified.) 



thin-walled phloem. The primary elements of the xylem, very narrow 

 spiral tracheides, are formed at the angles of the bundle, and from them 



