166 



for instance from Spitzbergen, late in July (19th and 23rd; 

 Andersson and Hesselman). On the whole, the nature of the 

 habitat plays an exceedingly prominent part with regard to the 

 late or early flowering in any particular district; but with 

 respect to phenological statements which have not been care- 

 fully illustrated and verified we cannot be too cautious; see 

 KiHLMANS remarks (10, pp. 54 and 65). 



The flowers are protandrous. 



Pollination undoubtedly takes place almost exclusively by 

 the aid of the wind. E. Warming (19, p. 116) was the first to 

 give the reasons for this, and later Skottsberg has defined 

 them more precisely; the reasons are: — the long filaments 

 (according to my measurements normally 7—9 mm.), which 

 are exceedingly thin (about 0*25 mm.), and have comparatively 

 large anthers; the perfectly smooth pollen; the large, somewhat 

 sticky stigmas, and several other features. Skottsberg protests, 

 with good reason, against Lindmans supposition (12, p. 35) 

 that the flowers are sometimes entomophilous. 



The formation of the flowers for the next period of growth 

 takes place very early; in material collected Sept. 5th (Kong 

 Oskarsham) the flower-rudiments were one millemetre long, 

 the length of the flower-rudiments in the spring in Arctic regions. 



Fruit seems to be borne abundantly by Empetrum in many 

 Arctic regions, but it must develop more quickly than in the 

 southern zones, if it is to become ripe. 



Warming found young fruits "even in the beginning of 

 July" (about 2 months later than in Denmark). He writes 

 later: "In the beginning of August 1884 the fruit was almost 

 ripe at Holstensborg" (21, p. 38). There is doubtless good 

 reason to believe, that when circumstances are favourable for 

 the development of the fruit, it ripens in August, attaining 

 the same size as in Denmark (about 7 mm. in length and 

 8 mm. in breadth), and producing the same number of seeds 

 capable of germination. 



