\NWI1S DE L'INSTITUT OCÉANOGRAPHIQUE 

 4 



H was not from purely scientific reasons that I began to use this apparatus; it was in 

 order to determine the quantity of plaice-food in the different parts ot our small Danish 

 w aters It was of importance to know this in connection with the transplantation of young 

 plaice, which has been set on foot by the Danish Government on my initiative. Later I 

 found out that the method was quite useful also in large waters and during the last few 

 years I have now. with the assistanceof the " Sallingsund " of the Danish Biological Sta- 

 tion and its crew, made about 2 co quantitative determinations each of io-5o samples, in 

 the Danish waters, which connect the North Sea with the Baltic and which comprise all 



Fig. 2. — Two bottom-samplers closed. 



the transitional stages with regard to biology and hydrography between these two so diffe- 

 rent seas. 



My original plan was only to determine the quantity of the animal life in each m 2 in 

 these waters, but I soon found that for comparative purposes I was obliged to determine 

 and chart the regions, which had at least a fairly similar population, and afterwards make 

 quantitative determinations of the value of eachofthese regions. In making these charts 

 my previous work on the Kattegat (Kanonbaaden Hauch's cruises) based on 5oo dredg- 

 ings, were of good help to me, especially as the depth and kind of bottom had already 

 been charted ; all that remained was to make asurvey of the distribution of the animals. 

 In that work I had already charted the distribution of each separate species but no survey 



