86 



Pirola imiflora L. (Fig. 4.) 

 The specimens are from Finmark: Alten (July 6, 1885, 

 Warming). The Danish specimens are from Tidsvilde Hegn and 

 from Hornbaeli Plantage. 



This species differs from the three described above in 

 regard to the leaf, the inner structure of the latter being much 



more dorsiventral , and 

 arranged on the whole 

 in a typical manner. 



The epidermis of the 

 upper and lower surface 

 have only slightly thick- 

 ened outer walls and 

 much undulating lateral 

 walls. Stomata occur 

 only on the lower surface 

 and are slightly projecting. 

 Hairs are absent. Chloro- 

 phyll grains occur in both 

 the upper and lower 

 epidermis. 



The upper layer of 

 the mesophyll is of pali- 



sade-form, and the cells 



Fig. 4. Pirola uniflora. 

 . -, r ■ . » 1 1 4u /1 are short and broad ; the 



7, Leaf in transverse section; below' the epidermis ' 



of tbe upper surface (es) a palisade-like layer of rest Of tllC meSOOhvll is 

 cells is seen. Cf. note p. 81. 1, 2 and 3, X about 

 120; 4 X about 250. (Finmark: Alten) (H. E. P.) loOSCly arranged witll 



large intercellular spaces, and consists as usual of irregu- 

 larly rounded thin-walled cells which branch but slightly and 

 are colourless in the spirit-material. In Danish specimens 

 the palisade-cells were somewhat longer and more slender than 

 in the specimens from Alten, otherwise there was no especial 

 difference between them. 



