The Plant-Life of Hare Island off the coast of West Greenland. 269 
In the above list the terms “rare,” “scarce,” “common,” etc. have reference 
only to those parts of Disco and Nugsuaq which have been quoted, and when a 
species is termed “rare” or “scarce,” it means that only a single or very few stations 
are known to me, but when the plant does occur, it ordinarily occurs in great 
quantities, sometimes in enormous numbers of individuals, e. g. Elyna, Elymus, Du- 
pontia, ete. 
The above list is not complete, as some rarer species also occur 
upon some of the adjacent coasts. But the 31 species here mentioned 
are so conspicuous that they certainly would not have been over- 
looked either by my son, or by myself, if they had come in our 
way. The reason for their absence may be of different kind. Firstly, 
we may exclude a difference of the climate as a cause for the lack 
of the above species. In the parts of Disco and Nugsuaq in ques- 
tion the climatic conditions are nearly equivalent to those of Hare 
Island, the south coast of Hare Island, if anything, being more 
favourable in that respect than the north coast of Disco. In regard 
to several species the non-existence may be due to the lack of favour- 
able habitats. This is without doubt the case with the five purely 
aquatic species, marked in the list with a W. Plants such as 
Braya, Lesquerella, Arabis arenicola, Taraxacum groenlandicum are 
along the shores of Waygat most common on mesozoic sands, but 
they also occur on morainic soil of basaltic origin. The conditions 
on Hare Island would in reality suit the majority of the species as 
well as do the conditions on Disco or on Nugsuaq, and the only 
reason for their absence seems to be the difficulties arctic plants 
encounter in their wandering. 
I hope I shall shortly be able in another paper to enter more into 
details upon the biology of the dispersal of arctic plants and concer- 
ning the conveying agencies that in arctic regions are of the greatest 
importance. Here, I shall only remark that according to my obser- 
vations on that subject, the seeds of all the species in the above list 
are spread by the agency of the wind during the winter with the 
exception of the aquatic species and the halophilous Plantago. 
The transportation by the agency of the wind in winter 
over hardened snow and frozen seas is an important 
factor "in the dispersal of plants in the’Arcties, but in 
our case, there are circumstances that often neutralize it, namely 
the fact that the straits separating Hare Island from the 
main-lands are very rarely covered with continuousice, 
even in the severest winter. The tidal currents are strong 
here and open strips of water will absorb the main part, if not all 
seeds carried by wind over the ice.! 
1 When sledging on sea-ice, I have often seen how enormous quantities of snow 
are blown into the sea, and how even a narrow streak of open water may absorb 
the whole amount of snow drifting over the surface of the ice. 
