Introduction. 



A wide field for zoological research, which has given, and will surely continue to give 

 results of the highest scientific interest, has been lately opened by the investigation of the 

 great depths of the sea, which had formerly been generally considered as void of all life, but 

 which have been found in some places to contain a wonderfully rich and varied animal world. 

 Such deep-sea investigations have indeed been occasionally made at various points of our 

 coast; and my Father gave already in 1864' a catalogue of 92 difi'erent forms of animal life, 

 which were discovered by him and by other Norwegian naturalists, at the great depth of 200 

 — 300 fathoms; and he had likewise previously — as early as 1850- — decidedly declared 

 himself opposed to the hypothesis set forth by Forbes, and subsequently generally adopted, 

 that the limit for the propagation of animal life in the depths of the sea should be fixed at 

 about 300 fathoms. It is however only quite recently that such deep sea investigations have 

 been conducted in a systematic manner on our coast. I had myself a particularly convenient 

 opportunity for such research during my stay in Lofoten, where depths of 300 fathoms and 

 more occur at a relatively small distance from land. I therefore determined, notwithstanding 

 the great difficulties connected with dredging at such great depths, and although I had only 

 an ordinary fishing-boat with a crew of 3 men at my disposal — to devote as much time 

 as I could to these investigations, abandoning the far easier, and as 1 then thought far more 

 productive, investigation of the smaller depths. The result of these my deep-sea researches 

 was however, great and interesting quite beyond all anticipation. I found to my great sur- 

 prise at this enormous depth — not, as might be presumed according to Forbes' hypothesis 

 — a poor and oppressed Fauna, but on the contrary a richly developed and varied animal 

 life; so that my Father was able in 1868' to increase the catalogue of the forms of animal 

 life observed at the depths of 200 — 300 fathoms, by tlie addition of not less than 335 species 

 (in all 427) of which nearly all were taken in one locality, namely at the fishing-place Skraa- 

 ven in Lofoten. And so far was I from observing any sign of diminished intensity in this 

 animal life at increased depths, that it seemed, on the contrary, as if there was just beginning 



' ,Bema3rkninger over det dyriske Livs Udbredning i Havcts Dybder." Christiania Videnskabs-Selskabs Forhand- 



linger for 1864. 

 ' ,Reise i Lofoten og Finmarkcn." 

 ' „Fortsatte Bemserkninger over det dyriske Livs Udbredning i Havcts Dybder". Chr. Vid.-Selsk. Forh. f. 1868. 



