projecting; also in the present case cells distinctly devoid of 

 tannin occur in the middle of the mesophyll. The epidermis 

 of the lower surface contains chlorophyll grains as in grandi- 

 flora. Warming has described in his paper, Exkursionen til 

 Skagen i Juli 1896 (see above), the anatomy of the leaf of 

 this species. He mentions a rather peculiar fact in regard to 

 the stomata. On the leaves of "light-plants" (from the Danish 

 downs) these organs cease to be functional at an early date, 

 so that they occur on older leaves as useless structures, but 

 in "shade-plants" (from woods: Tidsvilde Hegn, and Hornbæk 

 Plantage) they are well-developed and function normally. The 

 specimens which I have examined and which are from Finland 

 and the Faroes come nearest to the Danish wood-forms in this 

 respect. The stomata do not occur especially along the veins 

 as in Fir. grandiflora. In all other points it resembles Pir. 

 grandiflora. 



I have made no examination of the roots. 



Pirola secunda L. (Fig. 3). 



Of this species I have had for examination only spirit- 

 material from Disco (Porsild) and from Denmark. Further I 

 have investigated herbarium-specimens from Holstensborg in 

 Greenland, and Asbirgi in Iceland. 



The structure of the leaf corresponds in the main points 

 with that of Pir. grandiflora and of minor. 



The upper and lower epidermis are somewhat thicker than 

 in these forms. Stomata occur on both sides, but are fewer 

 in number on the upper surface, as is the case in Pir. minor. 

 On the latter surface the stomata are especially conflned to the 

 area near the veins of the leaves. Both the upper and lower 

 epidermis contain chlorophyll grains. Hydathodes occur, but 

 hairs are absent. 



The cells of the mesophyll are of the same form as those 

 of the mesophyll in the two above-mentioned species. No cells 



