75 
Migeation. — The plaice were caught and liberated in the inshore 
waters of the Northumberland coast, at the various trawling 
stations from Goswick Bay in the north to Blyth Bay in the south. 
They were all immature, measuring from about 7 to about 11 -in. 
in length. With the exception of two, the fish recovered have been 
captured also in the inshore waters of Northumberland, and in 
almost every case in the same bay where they were set free. Those 
recovered have been caught by the line and in trout nets, and I 
have therefore to thank the fishermen for their kind co-operation 
in carrying out the experiment. It is rather remarkable that, 
although it was not uncommon to catch the plaice which had just 
been marked in the trawl when the latter was passing over the same 
ground again during the course of one experiment, none of the 
labelled fish was caught by the trawl when the bay was subse- 
quently revisited in the same season. Four were recaptured at the 
trawling experiments of 1904 ; 1 (No. 88) at Alnmouth Bay ; 
2 (Nos. 178 and 183) at Blyth Bay; and 1 (No. 235) at Druridge 
Bay. 
The immature plaice of the inshore waters may then be said to 
be for the most part non-migratory. It is quite possible that much 
colder weather than prevailed last winter might have caused a 
migration into deeper water, and in such a case a return migration 
might have shown a general tendency in a definite direction such as 
resulted from Fulton’s experiments. But last winter at all events 
the great majority of the plaice remained in the inshore waters, and 
did not migrate as a rule from the bays. The rocks and the rough 
ground which limit the bays may therefore be considered to act 
as barriers to migration. 
Of the 61 plaice recovered only two made conspicuous migra- 
tions, and only seven may be said to have left the bays where they 
were liberated. The two just mentioned were liberated in Goswick 
Bay to the north of Holy Island on June 26th. One found its way 
to St. Andrew’s Bay, where it was captured on November 5th, and 
the other was caught on May 27th this year seven to eight miles 
east of May Island. On the same day at 6.15 a.m. 14 other plaice 
were marked and liberated at Goswick Bay, and these were all 
taken from Skate Roads, south of Holy Island. Six were recovered, 
the two. just mentioned, two at Goswick Bay, and two at Skate 
Roads. The latter are the only ones we have record of which offer 
us a hint at the homing instinct. As will be evident, however, the 
