25 
to the shore even at that season. It shows also that the plaice 
caught during the winter months are a sort of relic of this summer 
population, the same kind of plaice are represented in very much 
reduced numbers. 
These plaice are from two to five years old. It is plain, therefore, 
that the bays of the Northumberland coast support in the summer a 
large population of plaice from recently hatched to nearly mature 
in size and age ; and that this population suffers a great regression 
during the winter, indeed for rather more than half the 
year. At the beginning of this latter season, the plaice migrate 
into deeper water, and to a large extent outside the Committee’s 
district, returning again in the spring. 
The figures in Table Y. indicate, moreover, that the small two-year 
old plaice congregate in large numbers in the region of the stations 
in September and October, and immediately thereafter disappear — 
compare Skate Roads, August 29tli, and September 27th, 1907, and 
Alnmouth Bay, October 15th and November 12th, 1908. The 
previous experiments have shown that the same class and the 
two-year old fish of the season return about June. 
There is another point which it is important to note with 
reference to the migration in relation to tide. The successive catches 
at different phases of the tide may in the total be closely similar, 
and at the same time differ markedly as to the numbers in relation 
to size. For example, at Skate Roads on September 27th, 1907, 
when the catch per hour was almost exactly the same for five hours, 
the two-year old plaice w 7 ere got most conspicuously at the first 
and at the third haul ; the second haul presented the most 
larger and older fish. The first haul was made at mid-ebb, the 
second at the end of the ebb, and the third during the early part of 
the flow. 
D.\n. — In table YI., the catches of dabs at the same places and for 
the same time in each case are brought together. A comparison 
between this table and Table Y. serves again to illustrate the 
difference between the northern and the southern stations with 
regard to the proportional numbers of the two species. The 
table shows that the dabs caught in the summer have a range 
of size which is very similar to that presented by the plaice, only, 
as would naturally be expected, they tail off rapidly in numbers 
above 30 cm., and it is seldom that a size of 10 cm. is reached. 
A very small remnant of this population of summer dabs is left 
in the region of the stations during the winter. 
