DEPTHS OF THE OCEAN vii 



chapters the previous investigations of the " Michael Sars " in 

 the North Sea and in the Norwegian Sea generally have been 

 taken into consideration, in order to compare the physical and 

 biological conditions prevailing in northern waters with those in 

 the Atlantic. In this way it is hoped that the book as a whole 

 will present the student with a fairly complete epitome of recent 

 advances in the modern science of oceanography, even though 

 it has proved impossible to give a complete review of the 

 literature of the subject. 



The historical chapter and the chapter on the Depths and 

 Deposits of the Ocean have been prepared by Sir John Murray ; 

 that on Physical Oceanography by Dr. Helland- Hansen ; that 

 on Phytoplankton by Professor Gran ; and that on the Bottom 

 Fauna by Professor Appellof, while the chapters dealing with 

 the equipment of the ship, the working of the gear, the narra- 

 tive of the cruise, the fishes from the sea-bottom, the pelagic 

 animals, and general biology have been written by myself 



In the examination of the zoological collections I have 

 received most valuable assistance from Mr. James Grieg, 

 Mr. Einar Koefoed (who took part in the expedition and also 

 in the special examination of the fishes), Mr. Einar Lea, 

 and Mr. Oscar Sund. All the original drawings have been 

 made by Mr. Thorolv Rasmussen, who also took part in the 

 cruise, and was continually engaged in making drawings and 

 sketches on board ship. To all these gentlemen I acknowledge 

 my indebtedness. 



The biological collections have been distributed to 

 specialists in different parts of the world, and the following 

 have sent me preliminary reports on their results, which I 

 have been able to use in this book : — 



Mr. Paul Bjerkan, Bergen ; 



Dr. Kristine Bonnevie, Christiania ; 



Dr. August Brinkmann, Bergen ; 



Dr. Hjalmar Broch, Trondhjem ; 



