VIII 



12. Specimens of the finest roots of heather — preferably with 

 some earth attached — should be put in spirit (on account 

 of the threads of fungi which occur around the roots). 



The soil of the heaths as a whole requires to be tho- 

 roughly investigated, both with regard to the formation of 

 heath-mould and to ascertain Avhether grey heath-sand and 

 hardpan are formed in the same way as on the Jutland heaths. 



13. Leaves of flowering plants should be put in spirit, preferably 

 straight from the field, and should be accompanied by detailed 

 information regarding the dampness of the locality, exposition, 

 time of day when collected (at what o'clock), etc. 



14. Little is known as to how far the light during the night is 

 sufficient to produce carbonic acid-assimilation. This question 

 should be investigated if opportunity offers. This would pro- 

 bably be most easily done by wrapping the leaves in tinfoil 

 and keeping them from the light until the starch must have 

 disappeai'ed ; they should then be uncovered by night, some 

 of them — or portions of the same — should be put imme- 

 diately in spirit (marked in some Avay or other), and others 

 to be exposed to the light at night and put in spirit the next 

 morning. The experiment should be made at a favourable 

 temperature (the latter being noted). 



15. The flowering plants should be gathered with the parts under 

 the ground complete, and large enough to show how the 

 species grow (Avhetlier they have a permanent primary root? 

 whether runners? etc.). 



16. How do the plants manage in the loose debris which is con- 

 stantly sliding and which occurs upon and at the foot of so 

 many basalt mountains? How are they formed? Do the 

 roots go deep? Are they torn asunder? The vegetation is 

 doubtless very open and poor in such places — to what 

 degree, should be investigated. 



D. Other investigations. 



1. Drift-wood should be collected. 



2. Attention is especially directed to the occurrence of the two 

 different species of Dr y as and their intermediate forms. 



Copenhagen, July 4, 1898. 



