98 



transparent cells interrupted by trabeculæ of thicker-walled cells 

 with contents ; these are not, however, as distinctly developed 

 as in Andromeda and Ledum. The primary cortex falls off 

 very early, even by the end of the first year. The outermost 

 part of the secondary cortex consists of an ordinary cork-tissue 

 of no importance. 



Fig. 14. Loiseleuria jjrocumbeyis. 



Transverse section of stem ; several annual rings are discernable. X 180. 



(Greenland.) (Phot.) 



The annual growth of the wood is rather difficult to 

 demonstrate, because, as it appears, lines are formed in the 

 annual wood which resemble annual rings, but they can scarcely 

 be such. In some cases the annual rings are however distinct. 

 The spring wood is fairly sharply differentiated from that of the 

 summer (or autumn) (0. G. Petersen, p. 78). 



I had no material of the root for investigation. 



