well lighted up, so that we could see the small stones and piants and sometimes 

 a smelt, which did not seem to be disturbed by the light; but uo eels were 

 seen to pass the light when it was held steady. 



The projector was then placed iu the middle of the outlet, so that it only 

 lit up the one side. Its light was however so streng that the other half of the 

 outlet was not iu complete darkness, as the reflexion from obstacles, grass, bank " 

 etc, on the lighted side was strong. I wished to iuvestigate whether by lighting 

 up half the channel, the eels could be forced to migrate through the other half; 

 but this was only partially successful, as though the migration did not completely 

 stop, yet it was considerably diminished, apparently as a result of the reflexion. 

 Further, the streak of light from the projector was fairly broad so that the light 

 was not sufficiently concentrated, which may be easily altered however in the 

 future by means of a shutter. 



From this experiment under such fortuuate couditiou.s, only to be met 

 with on quite few days in the year, which confirmed the experiment (with petro- 

 leum lamps) made in 1904 by Cand. Otterstrøra at the same place, I have no doubt 

 that the migration of the eels can be completely stopped by means of light and 

 that the projector used might have stopped the migration in au outlet considerably 

 broader and somewhat deeper. 



The eels at Kilen are alraost all male eels, with 7 to 8 iu the Ib. ; all the 

 eels taken were fully developed silver eels. 



Whether the eel migrates chiefiy in the upper or lower water-layers, the 

 experiment gave uo good opportunity to iuvestigate, as the water was shallow, 

 2 to 3 feet deep. 



It was my intention therefore to test the action of the projector under 

 larger conditions out in the true Lim-Fjord at Oddesund, and some few experiments 

 were even made; but the conditions were not specially fortunate, so that uothiug 

 could be couciuded. 



On the other hånd, we were succesful later in the Little Belt in the moon- 

 less nights of October 1906 in observing the migrating eels up in the surface of 

 the water at night; this was managed by sailing along with »the projector lixed 

 to the bow in front of the »Sallingsund«. The eels were seen several nights, 

 but we never saw very many, 10 — 12 within a space of two hours and often but 

 a few, so that I cannot as yet sjieak with eertainty regarding whether it is a rule, 

 that the silver eels migrate u\> iu the water or not; but some do so. This obser- 

 vation agrees very well with that previously mentioned in the »Fiskeri-Tidende« 

 Nr. 4, 1906, p. 27. 



It may be further mentioned that auother tish, the butter-fish (Gmielhts vulgaris), 

 which lives quietly duriug the day below stones and such like, coraes right up to the 

 surface of the water at night; we saw many of them in the Liltle Belt during 

 the experiment mentioned and took many with a bucket. If such can wander 

 about in quantities iu the upper layers, it may be accepted that the eel is also 

 able to do this; and unless it be considered that the eel migrates as a rule in the 

 upper layers, I do not understand bow the surface currents, the wind and the 

 mooulight can have so great an influence on the migrations of the eel as they 

 actually have. 



