24P 



OUTLINES OF PLANT LIFE. 



mis (e/, fig. 205) ; the development of two or more layers of 

 epidermal cells (fig. 208) ; or the excretion of wax or of 

 varnish upon the surface of the epidermis. The latter often 





Fig. 



Fig, igg. Fig. 201. 



Fig. Tgg.— Prickly pear {Opuntia vulgaris) with flattened jointed stem and no leaves. 



About one fourth natural size.— After Frank. 

 Fig. 200. — Multicellular hairs of edelweiss. Magnified about 50 diam. — After Kemer. 

 Fig. 201. — Silky unicellular hairs of Convolvulus C7ieoruiii. Magnified about 50 diam. 



—After Kerner. 



Fig. 202. — T-shaped hairs of Artemisia mutellina. Magnified about 50 diam. — After 

 Kemer. 



becomes very thick, giving to the leaves a shiny appearance. 

 Wax is usually in the form of a bluish-white powder, which 

 can be readily wiped ofTwith the fingers, as from the surface 

 of fruits, such as plums or grapes, the leaf of cabbage, or the 



