PLATE IX. 



FIG. 



1. A leaf of Virginian Tobacco attached to stem, ~ n. s. 



2. Portion of skin from under surface, greatly magnified, to show the 



two forms of hairs (// /i) lying amongst the breathing pores, s. 



3. Hairs separated, and highly magnified. 



4. A transverse vertical section of portion of leaf- blade, with hairs 



and breathing pores on under surface. 



5. A horizontal section of midrib of leaf, magnified. 



6. A leaf of Burdock, | n. s. 



7. Hairs from under surface of leaf terminating in long delicate 



filaments, highly magnified. 



8. Horizontal section of midrib of leaf with lobed outline, and 



bundles of woody fibre separated. 



9. Leaf of Dock, ^ n. s. ; a, the stipule at base of stalk, detached. 



10. Club-shaped, striated hairs, from skin of midrib and veins, 



greatly magnified. 



11. Horizontal section of midrib, with lobed surface, and woody 



bundles separated. 



12. A portion of skin of under side of leaf blade, greatly magnified, 



to show the position of the glands Qf) amongst the breathing 

 pores (s). 



