- 179 - 



and 1905, at a time of year therefore when we were unable to make investigations 

 out in the Atlantic with the "Thor". 



In these years 3 specimens in all of the eel larvae (or eel young) were taken by the 

 "Helga" in November. The youngest was at the end of the 4th Stage and it is this 

 specimen which is figured on Plate VIII, Fig. 10. It was taken on Nov. 8th 1905 off the 

 west coast of Ireland (54°59' N., io°53' W.), thus like our September specimens beyond 

 the 1000 meters line. It is !of great interest that it was taken with a dip-net, being 

 seen swimming about on the surface at night along with two others. Two hauls were 

 made at the same place with a large triangular net with respectively 20O and 700 fathoms 

 of wire out, but no further specimens were taken (information from Mr. George P. Farran 

 of the "Helga"). 



We see from this that the eel larvae, even so far on in development as the end of 

 the 4th Stage, that is shortly before the transition to hemilarvae ("civelles", "elvers") are 

 found pelagically close to the surface (right on the surface at night), but still 

 over great depths. The migration to the coasts seems therefore to begin only when 

 the larvae have entered upon the 5th Stage. This is also shown by two other Irish 

 specimens which were taken to the west of Ireland on Nov. 4th and l6th 1904 (respec- 

 tively at 5l°50' N., ii°26' W., depth 129 fathoms and SS'-'SÔ'ao" N., ll°15'30" W., depth 

 7472 fathoms; the places are marked on the chart, Plate XI), and were already in the 

 beginning of the 5th Stage. The discovery of these two elvers is also of great 

 interest, as in the first place they are the only eel young from the previous spawning 

 which have been taken so early as November and secondly because they show that the 

 migration towards the coast has already begun in this month. As can be seen from the 

 Chart, they were found almost midway between the lOOO meter line and the west coast 

 of Ireland. They were taken in the dredge and trawl at the bottom during the day (see 

 further the list on p. 194). 



(d) Bathypelagic fish eggs (floating in deep water) are common in the Atlantic 

 Ocean. In the spring of 1904 I was already successful in detecting the occurrence 

 of pelagic fish eggs floating at great depths far from the surface in the Atlantic. I 

 could not determine at that time to what species these eggs belonged. I was able cer- 

 tainly to hatch out some few of them and was thus able to determine that they belonged 

 to species whose larvae (like for example those of the herring and eel families) had the 

 anus far back towards the end of the tail, but I could not get any further. The dis- 

 covery was therefore not published at that time, as I hoped I might find more material 

 later which would enable me to make a more exact determination. It has now been 

 possible to determine most of our bathypelagic eggs with certainty, the great majority of 

 them belonging to the deep-water salmonoid Argentina sihis^ 



During the 1905 investigations in the Atlantic I found bathypelagic fish eggs in such 

 abundance that we are clearly in sight of a phenomenon of very great significance 

 and obviously of great importance for the understanding of the biology of the deep water 

 fish-fauna. As this is likewise of interest in connection with the present investigations on 

 the eel I may give a brief account of it here'. 



1 See further JOHS. SCHMIDT, un the larval and postlarval development of the Argentines [Argenüna si/us 

 and A. sphyraend). (Meddel. Komm. Havundersogelser, Serie Fiskeri, Bind II, 1906). 



23' 



