CORDAITEAE 



533 



a strong sheath, which abuts, above and below, on a 

 hypodermal strand of fibres. Smaller hypodermal ribs 



Fir,. 192. — CordetUes, Leaves in transverse section. A. C. anguldsostriatus ('?), //, /, 

 hypodermal ribs of sclerenchyma ; j>, mesophyll ; </, bundle-sheath; a, centripetal 

 \ylem ; /, protoxylem ; &. centrifugal xyletn ; c, phloem ;_/J tissue connecting the 

 bundles. x 60. B. C. rhomb inervis. Here the ribs of sclerenchyma only occur in 

 connection with the bundles ; palisade-tissue and spongy parenchyma are differen- 

 tiated. X 50. C. C, lingulatus. Ribs as in E ; palisade-tissue well marked. 

 X 50. All after Renault. 



are interposed between the vascular bundles. The 

 bundle -sheaths are connected together laterally by 

 transverse bridles of thickened cells, which may perhaps 



