60 



out; but in the opeu flower the anthers are tilted backwards 

 and the pores then face upwards (Fig. 42 Д F). In the fully 

 open flower the pollen tetrads fall in quantities out of the 

 anthers without hindrance. 



The style is bent forwards and downwards (Fig. 42 yl, Б, K). 

 The stigma consists of five low protuberances (which appear to 

 be somewhat higher than those in the typical form of P. rotundi- 



folia) seated upon 

 the apex of the style 

 which is flat and 

 has a sharp edge 

 (Fig. 42 G]. 



I have not ob- 

 served secretion of 

 honey in any flowers 

 on the Greenland 

 plants; neither has 

 Ekstam in those from 

 Nova Zembla nor 

 PoppiDS in Finland. 

 Cross-pollination by 

 insects must be 

 of possible occur- 

 rence , and indeed 

 appears a necessity 

 (visitors in Finland, 

 cf. PoppiDs 1. c.) be- 

 cause in the fully open flower the pores of the anthers turn 

 upwards, away from the stigma, so that the pollen will have 

 difficulty in falling down spontaneously upon the latter. The 

 Greenland form grandiflora appears, however, to be somewhat 

 better adapted for self-pollination than the European Pirola 

 rotundifolia, because in the former the distance between the 

 pores and the stigma is only from 3 to 5 mm., while it is 6 



Fig. 41. Pirola rotundifolia. 

 (From Greenland, Tasuisak; Aug. 1896.) 



Shoot with scale-leaves and 3 year's growths with 

 fohage-leaves. (E.W., 1907.) 



