QB0UP8 OF TISSUES, OB TISSUE-SYSTEMS. 41 



com the central portion is composed of traclieary tissue, 

 consisting of pitted, spiral, ringed, and reticulated vessels 



Fro. 25. — Transverse section of flbro-vaacular bundle of Indian com. a, sid ■ 

 of bundle looking toward the circumference of the stem; i, side of bundle look- 

 ing toward the centre of the stem; §r, g, large pitted vessels; s, spiral vessel; r, 

 ring of an annular vessel; I, air-cavity formed by the breaking apart of the sur- 

 rounding cells; V, V, latticed cells, or soft bast, a form of sieve-tissue. Magnified 

 650 times. 



(Fig. 25, g, g, s, r, and the tissue between v — s, g — g"). 

 Lying by the side of the tracheary tissue (on its outer side 



