SUNIER: The Laboratory for Marine Investigations. 145 



For the collection of materials, investigators who come to work 

 in the Laboratory for Marine Investigations can accompany the members 

 of the Laboratory staff on their cruises with the research vessel "Brak" 

 (see Photo No. 9). 



Dr. Th MORTENSEN of Copenhagen, the first foreigner to visit the new 

 Laboratory, made a trip about the middle of 1922 lasting 14 days on the 

 "Brak" to the South- Western part of the Java Sea and the Strait of Sunda. 



On this trip Dr. MORTENSEN, with the help of the Sigsbee trawl, 

 brought together a large collection of bottoin-animals. 



The sphere of operations of the Laboratory scientific staff consists 

 of the collection of as exact and full data as possible concerning the life 

 and the environment of marine animals, and especially of those marine 

 organisms which are important from an economic standpoint. 



The main purpose is the obtaining of a true insight into the complex 

 conjuncture of natural, biological and hydrographical factors which in- 

 fluence the production of the fisheries or, in other words, the collection 

 of the knowledge by reason of which, ultimately, a rational exploitation 

 of the sea will be possible. 



It is not necessary to point out that this is a very extensive programme 

 when we consider the low numerical strength of the scientific staff of the 

 Laboratory ^). 



Accordingly the execution of this programme is going on only very 

 slowly. 



In connection herewith, the territory of research is limited to the shal- 

 low, preponderatingly neritic seas which belong to the continental shelf 

 situated in the Western half of the Netherlands East Indian Archipelago, 

 and which are of more importance as fishing grounds than the deep seas 

 of the Eastern half of Insulinde. 



A large number of temperature and salinity figures were collected in 

 this region, not only concerning the surface water, but just as much regar- 

 ding the deeper water layers. This work was done by Mr. K. M. Van 

 Weel, Captain in the Government Navy (Gouvernements Marine^, first as 

 captain of the research vessel "Brak" and later as assistant hydrographer 

 to the Laboratory for Marine Investigations. 



During the foreign leave of Mr. Van Weel the hydrographie data 

 were collected by his successor as captain of the research vessel, Mr. P. 

 C. Van Koesveld. 



In the isohaline and isotherm charts constructed from the numerous 

 temperature and salinity figures collected, the main horizontal movement 

 of the water layers at different depths and during different seasons is clearly 

 expressed. 



') The scientific staff of the Laboratory for Marine Investigations consists at the 

 moment of the author, as Head of the Laboratory, and Dr. H. C. D^lsman, as zoo- 

 logical assistant. 



