Cornaceæ. 



137 



smaller and with undulating sidewalls. This undulation is 

 more pronounced in leaves of Danish specimens than in 

 those from the Arctic (fig. 3). The sidewalls of the upper 

 surface are also undulating, but in a lesser degree, and also 

 in this case is found the same discrepancy between Danish 



Fig. 3. Cornus suecica. 

 A, Epidermis, upper surface, with a two-armed hair (Sukkertoppen, Greenland) ; B, Epi 

 dermis, upper surface (Maglemose, Denmark) ; C, Epidermis, lower surface (Sukkertoppen, 

 Greenland) ; 2>, Epidermis, lower surface (Maglemose, Denmark) ; A, B. С and D about '3%. 



and Arctic leaves, though less pronounced. The cuticula is 

 thin on both sides, and shows opposite the larger veins 

 fine stripes, running parallel to the longitudinal axis of 

 the leaf. 



Only the lower surface has stomata, these are placed 



