COUNCIL — JULY 1905 — APPEND. D 82 
in the North Sea from Esbjerg. If similar information were forthcoming for other 
regions, With at the same time similar data to that shown in Table I, it is evident, that 
a very full comparison of the relative richness of the different regions could be made. 
The last point to be considered here is the subdivision of the international 
area for the purposes of these statistical investigations. Several methods of sub- 
division have already been suggested, but the one represented on the Chart appended 
seems at once the simplest and most natural. 
Its main features are: 
1. Subdivision of the North Sea, Skager Rak and Kattegat according to depths 
(20, 40 and 60 meters), = 
9. subdivision of the coastal regions, 
3. subdivision of the North Sea into an eastern and western region at Ems 
ximately the2°E.L.; the Doggerbank being considered a separate area by itself. 
Besides the advantages of this method of subdivision, which will be apparent 
from the chart without further explanation, it has the further advantage of corre- 
sponding almost exactly with that already im use in England. It need only be 
pointed out, that further subdivision can readily be made for the purposes of spe- 
cial enquiry, also, that isolated grounds, deeper or shallower than the general depth 
of an area, can be considered separately, if sufficient material regarding them is 
obtainable ?. 
We have so far dealt only with the plaice, but all the principal species of 
food-fishes can be considered in the same way. It is one of the special advantages 
of this method, that a large and representative material regarding all species can 
be obtained within a short time and with comparatively little trouble. Further, 
it is only by dealing with large and representative material and by treating it on 
simple and broad lines as indicated here, that we shall be able to utilize the 
hydrographical and other biological data now being collected by the international 
investigations, in order to determine the main factors concerned in the distribution 
and variations in the distribution of the food-fishes. 
! In deference to opinions expressed at the meeting of the Statistical Section, a slight change has 
been made in the Chart and only the region of the North Sea south of the 60 m. line is now 
shown divided according to depth. 
C. G. Jon. Petersen 
H. M. Kyte 
A. C. JOHANSEN 
