— I8l — 



This showed therefore that most of the eggs sank in surface-water but remained 

 floating in water with the same specific gravity as bottom-water, which was a little greater 

 than that of the surface-water. 



The investigations at this station thus showed, that amongst deep water fishes 

 as amongst shallow-water fishes species occur in which the eggs are 

 pelagic, i. e. float in the water. But whereas the eggs of the shallow-water fishes 

 are generally to be found close to the surface, the eggs of the deep-water fishes 

 remain floating at great depths far from the surface, i.e. they are what we 

 call bathypelagic. 



I have repeatedly found these large bathypelagic fish eggs later everywhere in 

 the Atlantic south of Iceland and west of the Faeroes and British Isles 

 (i.e. in the "warm area"), where the depths were from ca. 500 — 1200 meters 

 and even greater. The months in which they were taken were May, June, July, 

 August and September'. I have never taken them on the surface, but always in 

 deeper water (e. g. in hauls with the young-fish trawl with 1800, 1700, 1500, 1200, 1000, 

 900, 800, 750 and 600 meters wire out without touching the bottom) so that there can 

 be no doubt they are really bathypelagic. The numbers found varied a great deal. Otten 

 there were several hundreds, even to a 1000, per l hour's haul with the young-fish trawl, 

 thus very considerable quantities 2, and we see from this that enormous masses of 

 pelagic fish eggs must be floating in the depths of the Atlantic without 

 coming up to the surface. 



I have not found bathypelagic fish eggs in the depths of the Northern Ocean with 

 its ice-cold water, though many hauls were made there in the course of years. They all 

 seem therefore to belong to Atlantic forms. 



Outside the Atlantic I have only taken such large bathypelagic fish eggs in the 

 Skager Rak (including the Norwegian Channel). A one hour's haul was made there 

 with the young-fish trawl 600 meters wire out in 57°52' N., 8°ol' E., depth 520 meters 

 on Sept. 6th 1905, and gave over 100 large bathypelagic eggs with yellow oil-globule. 

 On the other hand, only two were found in a 2 hour's haul with 300 meters wire and 

 none in two others with 65 meters ( l hour) and 25 meters (3/^ hour), which shows there- 

 fore that the eggs were here floating in deep water, not on the surface. All these 

 Skager Rak eggs belonged to Argentina silns like most of those from the Atlantic, 

 which could be determined amongst other characters by the number of the myomeres in 

 embryos freed from the egg. 



I have in this work given proof for believing that true bathypelagic fish eggs occur 

 at great depths in the ocean, where they hatch out to larvae, as in my opinion light is 

 thereby cast on the hitherto open question of the occurrence of the muraenoid eggs. 

 We saw in the Introduction (p. 155) that it had been accepted that the eggs of the eels 

 hitherto known (described by Raffaele and by Eigenmann) were pelagic but that it was 

 still an open question whether they belonged normally to deep water, where indeed no 

 one had taken them, but where Grassi supposed that they must normally occur, 

 or whether as Eigenmann imagined they occurred only exceptionally in deep water 



1 It should be noted here, that the condition in the other months of the year is unknown to us from 

 lack of observations. 



2 It must be remembered how deep the water-masses are in which they occur. 



