100 
The palisade-tissue consists of from 1 to 2 layers of cells 
as much as 70y in height; they are longest in the specimens 
from Härjedalen. The spongy parenchyma is relatively large 
— comparatively larger in this species than in Loiseleuria — and 
consists of non-branching or slightly branching cells elongated 
in various directions and not, as is usual in Loiseleuria, 
elongated chiefly transversely. Large intercellular spaces occur, 
owing to the form of the leaf and to the fact that the stomata 
Fig. 16. Phyllodoce coerulea. 
The leaf. 7, 2, Transverse section. 3, Multicellular hair. 
(Greenland: Sukkertoppen.) (E. Warming.) 
are well protected. No especial stereom nor aqueous tissue 
occur. 
The stem. The primary cortex has a thick epidermis 
with the same kind of hairs as on the leaf, and consists of 
transparent cells with thick walls which occur either singly or 
in trabecule. The pith has a similar structure. The primary 
cortex persists during the first and partly during the second 
year. The secondary cortex is formed by both regular and 
irregular cork-tissues which exhibit no point of interest. The 
