78 



THE LIVING CYCADS 



The most characteristic view is seen in longitudinal 

 sections cut at a right angle to a Hne from the pith to the 

 cortex (Fig. 27). Such sections show a lattice effect 

 caused by the association of very long wood cells and 

 the shorter cells of the "rays" which extend from the 



AftM- 



Fig. 24. — Zamia floridana: longitudinal section of the apex of a 

 large plant, showing three cone domes (c), the lower with bundles in 

 transverse section, the middle with bundles running to the peduncle 

 (p) of a mature cone, and the upper with bundles running to a young 

 cone; the new growing-point is at the right of the young cone; several 

 leaf traces (/) are shown. About 2| times natural size. 



pith to the cortex. These rays are full of starch and 

 crystals of calcium oxalate and are alive, while the long, 

 empty wood cells are dead. It is this arrangement of 

 long woody cells and shorter starchy cells which makes 

 the stem hard to cut with a saw. However, when the 

 stem becomes thoroughly dry and seasoned, it can be 

 cut and polished. 



