12 
PRESIDENT S ADDRESS. 
summer expansion of the great Atlantic eddy which circulates 
round the Sargasso Sea. The full effects of this periodic 
flood of warm salt water appear to be felt off the coasts of 
the North Sea as a rule in the autumn months, and to cause 
the seas on the coasts of Holland, Germany, and Sweden to 
reach their highest average level at this season of the year. 
Various phenomena connected with the migrations and 
spawning of important food-fishes, in addition to the examples 
already given, appear to be dependent on this periodic inflow 
of Atlantic water ; while variations in its volume and course 
from year to year appear to be correlated with significant 
changes in the distributions and migrations of fish. 
Professor McIntosh has already drawn attention to the 
numbers of oceanic species of Ccelenterate and other types 
which stream southwards along the East coast of Scotland 
during the summer months. I shall be much surprised if our 
investigations do not ultimately reveal a close relation between 
good and bad Herring seasons off the East Anglian coast and 
the annual fluctuations in the volume and character of this 
North Sea eddy from the Atlantic flood. 
Referring now more particularly to the English work in the 
North Sea under the international programme, I may say that 
the Marine Biological Association have naturally devoted 
most time during the first two years to the investigation of 
flat-fish problems. The migrations of Plaice have been 
studied by attaching numbered labels to the fish and setting 
them free in various localities. This method has proved a 
very fruitful one, and has enabled us already to form a picture 
of the seasonal migrations of Plaice in the south part of the 
North Sea, which in its essential features will probably be 
established as representing the normal sequence of events. 
Speaking broadly, the Plaice along the Dutch and Belgian 
coasts seem to display a general tendency in a north-westerly 
direction towards the more open waters of the North Sea 
during the spring and summer months ; while, during the same 
period, Plaice on the Dogger Bank seem to be fairly stationary. 
