president’s address. 
14 
coast. In fact, all along the English coast small Plaice are 
far less plentiful than on the continental grounds. It is 
customary to explain the latter fact as a consequence of the 
eastward drift of the floating eggs, but this explanation does 
not appear to fully cover the facts. The bottom deposits 
are very different on the opposite sides of the North Sea, 
and their character exerts a profound influence on the distri- 
bution of the invertebrate forms which serve as food for fishes, 
as well as upon the distribution of the fishes themselves. On 
the continental coast the bottom consists of fine sand, but 
along the greater part of the English coast the bottom consists 
of coarse sand and gravel. The former is favourable for the 
development of burrowing bivalves, which form the chief food 
of Plaice ; but coarse sand and gravel are highly unfavourable. 
The prevalence of these coarse deposits off the English coast 
appears to explain the relative'dearth of small Plaice inshore, 
as well as among the outlying banks off the Norfolk coast, 
while the large numbers of small Plaice found on the Leman 
Ground further off, must be mainly derived, not from the 
English shores, but by emigration from the Dutch coast — 
a result which is in agreement with the experimental evidence 
afforded by the marked fish. 
In conclusion, Ladies and Gentlemen, I have been able to 
give you but a rough sketch of the investigations in progress. 
I shall not have failed altogether, however, if I have conveyed 
a fair outline of the methods which are being employed in 
this last attempt to unravel the mysteries of the sea around us. 
When you reflect that work is being conducted on similar, 
lines on behalf of every country bordering upon the North 
and Baltic Seas, you will realise, I think, that the Governments 
concerned have embarked upon a historic enterprise, which 
is calculated in due course to yield durable results concerning 
the natural conditions which control the supply of fish in the 
North Sea and man’s power to modify them to his advantage. 
In this, as in other departments of human activity, knowledge 
alone can bring such power. 
