52 Fritz Johansen and I. C. Nielsen. 



"glimmering" movements keeps almost above the same place until 

 it falls to earth again. 



We do not forget either to study the freshwater lakes on such 

 an excursion ; at the banks especially we find a comparatively 

 rich animal life. The almost microscopic, reddish spring-tails are 

 constantly hopping about on the surface of the water; it is almost 

 impossible to capture them and when we at la^t get them into our 

 glass, they clamber up its vertical sides with the greatest ease. The 

 brick-red Hydrachnidae crawl about between the blades of grass, and 

 if they catch hold of a gnat larva, we see how they hook themselves 

 on to it and in spite of their prey's powerful writhings gradualh' 

 suck out its substance. The most characteristic animals are however 

 the Apiis glacialis, of which we now meet with both the young 

 and the full-grown individuals; they are continually in movement, 

 sometimes burying themselves down into the soft mud? sometimes 

 "creeping" over the bottom, whilst their swimming-feet make ele- 

 gantly winding tracks in the brownish yellow sand. The Ostracoda 

 collect about the dead animals (e. g. Apus) and devour them; they 

 are the scavengers of the lakes and wander slowly over the bottom; 

 leaving the giddy Daphnidae to do the springing about up in the 

 water. 



It is now late in the day. We have wandered far about over 

 the wide plains, following the water-courses from the base of the 

 high land down to the sea. We have passed over boggy patches 

 and gravelly tracts, taking occasional leaps on to the large boulders 

 on our way, and walked along the banks of the lakes. To end up 

 our excursion we may now go towards the fells and find out what 

 insects are met with, as we gradually mount higher up. On the 

 slopes of the fells which bear some vegetation we now and then 

 see a butterfly (Argynnis, Cidaria, Penthina), but these gradually dis- 

 appear {Cidaria goes up the highest), and as the vegetation grows 

 thinner (grass and a few tufts of Cassiope, Papauer and Saxifraga) 

 the otherwise so common Bombus likewise disappears. The ground 

 now consists mainly of bare rock, with here and there a small 

 terrace of gravel; but no lakes are seen, with the advantage that no 

 gnats are found here either. The only insects now seen are Tipiila 

 arciica and various flies (especially the earlier mentioned Melanostoma), 

 and when we come to a snow drift we see the same and other 

 insects out over the white surface, sitting in the holes in the snow 

 the sun has melted round about them. It is probably the wind 

 that has brought them here, and the strong light from the white snow 

 has then completely blinded them, so that they have fallen down 

 and helplessly perished. That thev are not there of their own free 



