98 HISTOLOGY OF ANGIOSPERM STEM, &OOT> ETf. 



Fig. 27. Part of a Transverse Section of Stem of Maize. 



PROTOPHLOEM 

 SIEVE TUBES 

 COMPANION CELLS 



LARGE PITTED 

 VESSELS 



SMALL PITTED 

 VESSELS 



SPIRAL AND 

 ANNULAR VESSELS 



XYLEM PARENCHYMA 



LYSIGENOUS CAVITY 

 SCLERENCHYMA 



Fig. 28,^-Tran8Yerse Section of Vascular Bundle of Maize. 



