Primulaceae. 177 



embryonic leaves of the rejuvenation bud are developed as 

 foliage-leaves during the summer. The succeeding leaves 

 remain as scale-leaves, forming a protection for the young 

 tissues of the bud, which in the following spring will develop 

 into foliage-leaves, and terminate in the formation of the pe- 

 duncle. 



The duration of the adventitious roots is similar to that 

 of the preceding species. 



Apparently Pr. sibirica never developes more than one 

 peduncle during one period of growth ; at least, I have seen no 

 specimens, which show indications of the autumnal rosette 

 developing its peduncle during the same year as the parent- 

 shoot. 



The peduncle bears only a few flowers, and frequently only 

 one of these attains to full development. But two subtending 

 leaves at least are always present, and in the axil of the one 

 which apparently bears no flower there is a microscopic rudi- 

 ment of a flower-bud (fig. 6, J). Amongst the plants from 

 Bosekop a few specimens were found to have four-partite 

 flowers. The diameter of the limb of the corolla varies 

 from 10 — 15 mm; the colour is a light hlac (Blytt), but 

 according to Warming (1886 b) there is a white variety 

 at Alten. 



The biology of flower has been fully dealt with by 

 E. Warming (1886, a, p. 27), who states as follows: "As 

 regards the specimens from Alten, the following observa- 

 tions have been made: Normally developed, they are distinctly 

 heterostylous, the figures showing the differences. According 

 to my experience, the forms illustrated in fig. 8 (here re- 

 produced as fig. 6) С and D, must be looked upon as the 

 most common forms. In the long-styled flower the stigma 

 is just in the mouth of the tube, level with the dark-yellow, 

 wavy ring, which is present in this species as well as in Pr. 



stricta and other species. The very same differences known 

 XXXVII. 12 



