president’s address. 
13 
On the approach of winter the fish on the Dogger Bank seem to 
scatter radially in all directions, and a fairly general south- 
ward movement is evinced in the area south of the Bank. 
So great is the disturbance of the sea bottom during these 
winter gales on the shallower central grounds such as the 
Dogger and Well Banks, that the Hydroid Zoophytes, which 
are so abundant in these localities, are rolled by wave-action 
into compact fibrous balls from 4 to 8 inches in diameter. 
[Specimens of these “ Surf-balls ” were exhibited, consisting 
of Obclia longissima on the Dogger Bank, and of Hydrallmania 
falcata and Sertularia abietina on the Well Bank.] 
The growth of Plaice has been shown by the transplantation 
of small marked fish to be three or four times as rapid on the 
Dogger Bank as on the shallow coastal grounds which form 
their natural habitat, a difference of great scientific as well 
as practical interest. 
The investigation of the age of fishes has been greatly 
facilitated during recent years by the discovery that the 
concentric markings exhibited by the scales, otoliths, vertebrae, 
and other skeletal structures are merely expressions of the 
annual periodicity of the growth of fishes, like the rings seen 
in the section of a tree. The study of the otoliths of Plaice 
of different size from various localities has already enabled 
us to compare the rate of growth on various coastal grounds 
with great exactitude. 
Some results of the trawling investigations in the neighbour- 
hood of the Norfolk coast will doubtless interest the members 
of the Society. It has been found in nearly all localities that 
the abundance of small Plaice steadily decreases with increasing 
depth and distance from shore. The distribution of Plaice 
between the Norfolk coast and the Dogger Bank furnishes 
a remarkable exception to this rule, as small plaice have been 
found to be much more abundant on the Leman Ground, 
50 miles from shore, than among the intervening banks 
nearer the Norfolk coast. On the other hand, the normal 
conditions prevail between the Leman Ground and the Dutch 
