The Insects of the 'Danmark" Expedition. 37 



in addition to the common plants mentioned above under the dry 

 gravel plains. Naturally, however, there are also many places where 

 all the plants of the species mentioned are found growing together, 

 especially if the places are sheltered or damp. 



It is difficult to give a general account of the temperature 

 conditions at the different seasons, which indeed are of vital im- 

 portance to insect life in North-East Greenland, as the three sum- 

 mers and two winters the Expedition spent there were so différent 

 from one another (see the account of the meteorology). In general, 

 however, the following may be said. 



The summer is considered to end a little after the beginning of 

 September (about the 7th j, when the temperature sinks somewhat 

 abruptly, being even in the daytime under the freezing-point (mean 

 temperature ca. — 5°^ minimum —10° to — 15°), though the first, 

 persistent snow usually falls only at the end of the month. During 

 the most of August however the night temperature becomes regularly 

 more and more negative (sen below, under August). 



The winter may be considered, as far as temperature is con- 

 cerned, to extend from September to April, both months inclusive. 

 The lowest winter temperature, which was taken at "Danmark's 

 Harbour", was ca. —40°. The snow-fall in the winter varies from 

 year to year. Usually the snow comes with strong, north-westerly 

 storms, especially at the beginning of the dark period (November) 

 and towards the end of the winter (March). 



The summer may be divided into 3 periods: an early summer 

 (May and first half of June), high summer (until the middle of 

 August) and late summer (until the first week in September). 



The first half of May is in general different from tfie last half 

 We then have usually clear, calm weather with a temperature at 

 noon of up to ca. —5° and at night of ca. — 15°; but as the month 

 advances, this great difference in temperature between day and night 

 becomes less distinct, heavy fogs or strong winds being the rule. 

 Frost at night is now less in general, and the temperature at noon 

 may on a few days reach +5°. 



In June fogs and winds also prevail during a greater or fewer 

 number of days, but the mean temperature is positive, a few degrees 

 above 0°, even though frost at night (down to ca. — 7°) is frecjuent 



1 All the temperatures are (Celsius. 



