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lu order to obtaiu some pelagic eggs for investigation we fished with the pelagic 

 net at a depth of 15 fathoms. The result was 70 eggs in 5 minutes. 



As regards the young fish, we wished to determine what was to the found 

 in the surface water as well as in the bottom. We thereJore made two hauls with 

 the young-fish trawl, the buoy attached, and ior the first haul let the line of the 

 buoy have a length of 10 fathoms; we tims made sure that the trawl went no 

 deeper than this. The result was 12 young in 30 minutes. We now gave the buoy 

 more line, so that the trawl according to our calculatiou might fish at a depth of 

 ca. 16 fathoms. The result showed, that we had now reached down to where the 

 young fish were, as we obtained ca. 260 specimens in one haul of 10 minutes. 

 The difference is strikiug, the first haul as mentioned oniy giving 12 in 30 minutes. 



At most of our stations we were satisfied with fewer determinations of 

 salinity, as we could judge beforehand, from the position of the station, at what 

 depth approximately we should meet with the boundary between the surface and 

 bottom water, a confii-matiou of our supposition was therefore sufficient. If things 

 turned out differently from what we expected, we put the water-sampler down to 

 a different depth. 



As may be judged from the foregoing, our hydrographic observations are 

 to be considered essentially as a means of assisting our investigations, as we used 

 these to obtain some notion of at what depths the pelagic fish eggs and young 

 were to be found. 



There has been no reason for the Biologicai Station to undertake exten- 

 sive investigations into the conditious of temperature and salinity in Danisli waters, 

 as such investigations have been carried on for a number of years through the 

 instrumentality of the Danish Meteorological lustitute, in cooperation since 1902 with 

 the "Hydrografisk Laboratormm" .*) These observations are taken daily, partly from 

 piaces at the coast, partlj' from some of the lightships stationed in Danish waters. 

 Determinations of temperature and salinity both on the surface and at different 

 depths to the bottom are taken at the ligthships, and although these do not lie 

 at the deepest spots, yet the results obtained give a good insight into the hydro- 

 graphical conditions of the different regions. The direction and rate of the surface- 

 current, the direction and force of the wind and other meteorological conditions are 

 also noted at the lightships. All the observations mentioned are published by the 

 Danish Meteorological Institute in the "Naidishmcteorologisl; Aarhog" . From the 

 summary tables in that work the hydrographical conditions at the various piaces 

 of observation can be followed from day to day throughout the year; tiie main 

 features of the hydrographical conditions in Danish waters can therefore be 

 ascertained from them. 



A eomparison of the observations from the hghtships shows that the upper 

 water-laj'ers are everywhere of less salinity than the deeper. The salinitj' does 

 not increase uniformly from the surface to the bottom, however, as a layer can 

 always be detected at a greater or less distance from the surface, in which the 



* Qnarterly hydrographical obsei-vations are al.so conducted in Danii^Ii water.s as part 

 of the international investigacion.s. As theae give no information regarding the frequent hydro- 

 graphic changes, I have jiaid no attention to tlieni in thif worlc, Imt liave only nsed the daily 

 returns from the lightships. 



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