DESCRIPTION OF PLATE VI. 



Fig. 1. — Liquidambar styraciflua (red or sweet gum): cross section showing 

 size and distribution of pores, width of rays, and arrangement of wood fibres in 

 radial rows. 



Fig. 2. — Liriodendron tulipifera (yellow poplar or tulip-tree) : cross section 

 showing size and distribution of pores, and thin layer of wood-parenchyma cells 

 marking outer limit of growth ring. 



Fig. 3. — Magnolia acuminata (cucumber tree): tangential section showing 

 vessels with scalariform bordered pits, and the small biseriate rays. 



Fig. 4. — Liriodendron tulipifera: tangential section showing vessels with 

 ordinary bordered pits, and the comparatively large 3-5-seriate rays. 



Fig. 5. — JUsculus glabra (Ohio buckeye) : cross section showing uniform dis- 

 tribution of pores and rays. 



Fig. 6. — The same: tangential section showing very fine uniseriate rays, 

 irregularly disposed. 



