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From our southernmost station north of the h-ish bank (55°56' N., 9''40' W. ; depth 

 1240—1470 meters) we then went southwards on the I2th of June. We had four stations 

 on the Irish hanlv (depth: 116, 102, 130, 143 meters) but found no eel larvae. Our next 

 station lay at 5l°32' N., 12°03' W. with depths: 980, 1040, 1090, 1330, 960, 1420, 1290, 

 1060 meters. Six hauls of 2 hours each were made here and one of 1 hour, which gave 

 in all 20 Leptocephahis brevirostris. The greatest number in a haul was 6. This was 

 clearly an advance on the hauls at the station to the north of the h-ish bank and I con- 

 cluded therefore to go still further south. At the next station (57°00' N., 11 "43' W. ; 

 depths 1340, 1020, 1370, 1210, 1350, 850, 1400 meters) we took as many as 38 spe- 

 cimens in a 2 hours haul (another haul gave 22, a third 18, etc.). Some hauls were 

 also made over the central part of the plateau off the English Channel with depths of 

 1000—2000 meters, and here on June 24th (49°25' N., i2°20'W. ; depths 1280, 1310, 

 1350, 1230, 1270, 1310, 1330 meters) we took up to 70 Leptocephahts bj'cvirosir^'s 

 in a 2 hours haul. 



We thus succeeded in finding the larvae of the eel in numbers which must undoubt- 

 edly be considered as considerable, when we consider the great extent of water in which 

 they occur. It should be noted also that the greatest quantities of Leptocephali were 

 taken off the mouth of the English Channel and mainly over depths of 1000—1500 meters. 

 The view that the great majority of the North European eels migrate to the Atlantic 

 through the English Channel thus gained in probability. To make the investigations as 

 complete as possible in this regard I resolved to try to the south of the 1000—2000 meter 

 plateau lying off the English Channel. The most southerly station where Leptocephahts 

 brevirostris was found lay off Brittany at 48°09' N., 8°30' W. (depths 600, 995, 608 

 meters). Here 2 specimens were taken in a 2 hours haul with the smaller model of 

 the young-fish trawl (with 300 meters wire out) and 4 specimens in another haul of 

 4 hours'. I tried at several places still further to the south (e. g. 47°47' N., 8°oo'W. ; 

 depths 830, 1800, 1600, 740 meters and 47°13' N., 6°12' W. ; depths 1500, 905, 1080 

 metersj but could find no Leptocephahts brevirostris at any of these stations. The 

 condition to the south of the 1000—2000 meters plateau was thus apparently similar to 

 that north of the plateau, that is to say, the quantities of Leptocephali were much smaller 

 than on the plateau itself. 



I was thus justified in considering the investigation, to determine where the largest 

 numbers of the larvae of the eel were to be found in the parts of the Atlantic nearest to 

 the North Sea, at an end for the time being, and after taking further hauls in the mouth 

 of the English Channel in shallower water (less than 200 meters) without finding any 

 Leptocephali, the "Thor" steamed to Plymouth and thence to Esbjerg. 



During July and August the "Thor" was again engaged by the investigations at 

 Iceland where I found an opportunity of submitting our specimens of Lcptocephaliis bre- 

 virostris to a somewhat closer examination. This showed inter alia that the alimentary 



I On account of a very heavy southwesterly swell we could not use here the large model of young- 

 fish trawl, which is more liable to be burst by the waves on pulling in than the smaller, I estimate the fishing 

 capacity of the larger model as approximately double that of the smaller. For the rest there was apparently 

 no question of the heavy swell causing any great diminution in the catches, as 1 could judge h-om the quan- 

 tities of the plankton otherwise. Further the weather at the more southerly stations where we found no Lep- 

 tocephali (cf. Chart PI. X) was good, so that we were able to work with the large young-fish trawl. 



