408 Fr. J. Mathiesen. 



shoot is elongated in a runner-like manner, the new shoots 

 generally appear near the spot where it begins to bend up- 

 wards, but if it is short and vertical, the new shoots most 

 frequently appear at the base — sometimes, however, also 

 higher up; as an exception, shoots ("'enriching-shoots") may 

 appear in the axils of the lowermost foliage-leaves: such 

 shoots, however, will probably be always purely vegetative 

 and terminate their development in the same year as the 

 parent-shoot. After flowering and fruit-setting, the latter 

 shoot dies down to immediately above the innovation-shoots. 



Innovation-shoots are generally developed to the number 

 of two on the parent-shoots; 11^ and IP in A and 1 11^ and 

 ///^ in D are seen to have arisen in the axils of two opposite 

 scale-leaves; this is most frequently the case, and explains 

 the fact why two flower-bearing axes are frequently found 

 to stand together. In Fig. 15, D a non-expanded bud is seen 

 in the axil of the first scale-leaf to the right of the subtending 

 leaves of the innovation-shoots. 



The innovation-shoots are developed rather late in the 

 Arctic summer; in the abundant herbarium-material from 

 Greenland which I have at my disposal I never found the 

 young shoots to be visible in individuals collected in June — 

 July, whereas in those collected in August they were about 

 one centimetre long. 



This does not quite agree with the statement of Hein- 

 RiCHER, according to which they already expand simultane- 

 ously with the foliage-leaves of the mother-shoot. The dif- 

 ference may perhaps be explained by the more unfavourable 

 conditions of growth, presented by the Arctic summer, in 

 which the building-up of new organs can be compelled to 

 extend over a longer space of time. 



The same author states, that small buds for the inno- 

 vation-shoots are already to be found the year previous to 



