Scrophulariaceae. 415 



der Weiden- und Waldregionen Lapplands, kann aber diese 

 Art im Hochgebirge sich nur an den viel Wårme darbieten- 

 den Stellen behaupten, mogen letztere auch viel trockenen 

 sein, als es gewohnlich in dem Tieflande der Fall ist." 



In the Alps it grows on "alle Formen alp. Wiesen und 

 den Quellfluren von den Vorbergen bis gegen die Nivalregion 

 (Schroter)". 



In the Arctics Bartschia belongs to the group of piants 

 of later summer, which is easily understood when one con- 

 siders the considerable vegetative work the shoots must 

 carry out, before flowering can take place. 



Anatom y. The Root. An adventitious root, about 

 1 mm thick, showed the following structure: The epidermis 

 had died away, only here and there a few of its cells remained 

 in a collapsed condition. The outermost layer of the primary 

 cortex had cuticularized cell-walls; in many of its cells a 

 division had taken place during growth, and in these cells 

 one very thin, non-cuticularised radial wall was found. The 

 cells in the inner layers of the cortex were distinctly tan- 

 gentially elongated and were likewise divided secondarily by 

 thin radial walls — in the cells of the endodermis as many 

 as four such walls were found. The wall of each of the ori- 

 ginal endodermal cells is in its whole circumference furnished 

 with a cuticularized layer, but as in the exodermis, the thin 

 radial walls which had developed later, were not cuticularised 

 here either. The root was 3-rayed; in transverse section the 

 xylem-part now formed a circular bundle, consisting of Ves- 

 sels and wood-fibres, since the cambium had commenced its 

 activity all the way round, The epidermis evidently dies 

 away very early; even in a root hardly 0.5 mm in thickness, 

 the epidermal cells were found in a collapsed condition. 



The root of 5 milHmetres thickness, with which the indi- 

 vidual from West Greenland, mentioned above, was fur- 



27* 



