60 



Knud Jessen. 



(Scandinavia). He writes that the anthers are introrse and 

 the filaments are bent inwards so that the anthers are sepa- 

 rated by only У2 mm. or even less from the stigmas, and 

 stand at a somewhat higher level than the latter; therefore 



Fig. 23. Sibbaldia procumbens. 



A, Flower seen from above. The disk (d) curves outwards between the stamens towards 

 the petals (about =/1). B, Longitudinal section of a flower; the anthers are almost in con- 

 tact with the stigmas ('Vi). C, Carpel with germinating pollen and an anther with open 

 pollen-sacs from flower from Kongsvold in Norway (about '-"/1). Drawn by Eu g. Warming. 



he thinks it is probable that self-pollination takes place. 

 LiNDMAN says that the flower agrees with Müller's Fig. 87. 

 As Fig. 23, A shows, there is a disk that curves towards the 

 petals. 



Dryas octopetala L. and D. integrifolia Vahl. 



Lit. BucHENAu and Focke, 1872. Holm, 1885. Warming, 

 1886, a; 1887. Lindman, 1887. Kihlman, 1890, p. 229. 

 Wagner, 1892. Hartz, 1894, p. 48; 1895, a, pp. 288, 300 

 and 311; 1895, b. Jonsson, 1895. Norman, 1895. Ekstam, 

 1897 and 1898. Kruch, 1897. Abromeit, 1899. Andersson 

 and Hesselman, 1900. Hesselman, 1900. A. Cleve, 1901, p. 

 45. DusÉN, 1901. Knothe, 1902. Schröter, 1904. Hag- 

 lund, 1905. Simmons, 1906. Sylvén, 1906. Hollstein, 1907. 



These two species are treated here jointly for brevity's 

 sake, as they only differ in a few morphological and ana- 

 tomical points. As regards their mutual systematic relation 



