LaD'ma. M. Lo-Ti^JoTV, del 



Fig. 8i. — Dioon spinnlosum: radial longitudinal section, showing union of leaf traces 

 with the vascular cylinder. Most of the tracheids of the leaf trace are scalariform; those 

 of the cylinder are pitted; X 55.— After Dr. La Dema M. Langdon.-m^ 



Fig. 82. — Dioon ediilc: photograph of surface view of apex of stem, showing a cone 

 dome with its bundles going to a cone, and, to the left of it, a similar scries of bundles 

 going to the new apc.x, which is producing leaves; below is a cone dome with some of the 

 bundles cut across. — After Chamberlain.'" 



