1907] HOLM—RUELLIA AND DIANTHERA 329 
seven steles, one in the center, six near the periphery; sand s, the four steles that 
fuse together in the node. 
Fic. ro. Epidermis of upper face of leaf, showing a glandular hair and a 
stoma, viewed en face. 320. 
Fic. 11. Epidermis and a glandular hair of leaf, transverse section. > 320. 
Fic. 12. Epidermis of lower face of leaf with a stoma. 320. 
PLATE XII 
Fic. 13. Transverse section of stem internode, showing part of peripheral 
stele: c, cortex; end, endodermis; st, stereome; 1, leptome. 400. 
Fic. 14. The innermost face of same stele (fig. 13), showing the continuous 
endodermis, some strands of Ieptome (/), and the large, thin-walled pith (9). 
X 400, 
Fic. 15. Tranverse section of stem internode, showing the locally, very heavily 
thickened cell walls of the collenchyma inside epidermis (ep). 
Fic. 16. Transverse section of rhizome, showing beginning jamntan of cork 
in apiderssia (ep). 
Fic. 17. Cortex of aren transverse section. X75. 
Fic. 18. Transverse section of rhizome, showing endodermis (end) and lep- 
tome with raphidines. 560 
Fic. 19. Transverse section of a node (submersed), showing the very thick- 
walled, branched cells of cortex. 240. 
Fic. 20. Tranverse section of an internode (submersed), showing the open 
ee X15 
. Transverse section of an aerial internode, showing collenchyma 
a an pls of cortex (c). 320. 
Fic. 22. Transverse section of lateral portion of leaf, showing the ventral 
epidermis ae and the palisdae tissue (p); below is the pneumatic tissue and 
dorsal ae X 240. 
IG. 23. Transverse section of leaf, showing palisades inside the dorsal epi- 
dermis a, and underneath the midrib. 240. 
Fic. 24. Stoma of upper face of leaf. 320. 
4 
