121 
veloped epidermis. The secondary cortex is found early in June 
and consists of regularly arranged cork-cells (Secersrepr). The 
limit between the yearly rings of growth in the wood is not 
sharply defined, neither is there any difference between the 
spring and summer (or autumn) wood. 
The roots have not been investigated (cf. HesseLman). 
Vaccinium Vitis-idæa L. (forma pumila Hornemann). 
(Figs. 32—33.) 
SEGERSTEDT, p.26. O.G. Petersen, p. 81. Tepm, 1892, p. 74. 
Maury, 1887, p. 108. Hesserman 1900, p. 27. 
I have had specimens for investigation from the following 
localities: — West Greenland: Isortok (June 8, Kornerup); Kri- 
stianshaab (July 26, 1884, Hartz 1890). Norway: Bosekop (July 9, 
1885, E. W.); Käfjord (July 10 and 15, E. W.); Tromsö (July 15, 
1884, E. W.); (Dovre) Kongsvold (July 13, 1887, E. W.). 
The leaf has no special protective hairs. 
The upper and =e 
SES 
= ) BZ ñ IV 
vos à NT )) 
lower epidermis have 
much-thickened outer 
walls, with cuticle and 
beneath that à cuti- 
cularized layer, and 
slightly undulating, 
thickened lateral walls 
with numerous pores. 
Chlorophyll grains oc- 
cur in the lower epi- ) 
dermis. In small hol- 2: SS 
4 
lows on the lower Fig. 32. Vaccinium Vitis-idea. 
surface multicellular The leaf. Cf. note p.81. (Greenland.) (H.E.P.) 
(glandular) hairs occur which are, however, of no importance 
as protective devices. The stomata are confined to the lower 
surface and do not project. The outermost layer of the inner 
