Primulaceae. 



199 



II. multicellular, thickwalled and most frequently branched 

 cover-hairs with a warty cuticle; various forms are depicted 

 in fig. 17, Z), E and F; D and E showing the thickness of 

 the walls. Stomates, surrounded by 4 — 5 cells, are present 



Fig. 17. Androsaces septentrionalis . 

 A, the epidermis of the upper surface of the leaf. Б, the epidermis of the lower surface 

 of the leaf. C, transverse section of the leaf; the vascular strand to the left shows collen- 

 chyma-like thickened tissue on the lower side. D, E and F, different forms of cover-hair; 

 D and E are seen in optical section. G, epidermal cells from the upper siu-face of the leaf, 

 with contents of spheroidal formations. (C, obj. 4, oc. 4; the rest, obj. 4, oc. 6.) (Öland.) 



on both surfaces of the leaf, but there are about double as 

 many on the lower than on the upper surface, the propor- 

 tion varying only slightly in plants from different habitats. 



