i88 



PLANT ORGANS OR PARTS OF PLANTS. 



there a few hairs may be seen on the veins of the under 

 side and also on the petiole. In this latter situation they 

 are more numerous and larger. The younger leaves are 

 more abundantly provided with hairs, and these also have 



Fig. 48. — Belladonna Leaf in Powder. 

 Epi, Epidermis, to right in transverse section; to left, superficial 

 view, showing contorted and wavy cell outlines and the wavy mark- 

 ings of the epidermal cells which are quite characteristic: ST, Stomata; 

 H, simple multicellular hairs; G, glands and glandular hairs; M, 

 parenchymatic tissue of the mesophyll; Pr, parenchyma near the 

 veins, vessels of the ribs and delicate fibre-like elements; C, to left, 

 filled with crystal sand; to right, rosette-shaped crystal; these last 

 being rare; O, parenchymatic cell with crystal sand; V, vessels. 



small-Stalked glandular cells. The upper surface is dark- 

 green, the lower lighter, grayish-green, showing whitish 

 spots; these locate the cells containing the crystal sand 

 of oxalate of calcium. 



Histology. — Both upper and lower surfaces of the leaf 



