SEA-FISHERIES LABORATORY. 225 
GENERAL SUMMARY OF THE RESULTS OF THE 
PLAICE-MARKING EXPERIMENTS CARRIED 
OUT DURING THE YEARS 1904-1910. 
By JAMES JOHNSTONE. 
INTRODUCTION AND METHODS. 
STATIONS. 
RESULTS WITH RESPECT TO MIGRATIONS. 
GROWTH-RATE OF PLAICE IN THE IRISH SEA 
AND ST. GEORGE’S CHANNEL. 
5. TABLES AND CHARTS, 
Pe rob 
1. INTRODUCTION AND METHODS. 
Experiments in marking and liberating living plaice 
were commenced in 1904 and were continued until the 
beginning of the year 1908; when, for various reasons, 
the investigations were discontinued. Short reports on 
the results of the separate experiments have been 
published in previous years,* but these have necessarily 
been incomplete since they dealt with data which were 
subsequently supplemented. Since no experiments have 
been made during the years 1909 and 1910, it is probable 
that no more marked fishes liberated during the period 
covered by the experiments will be recaptured. I 
propose, therefore, to give a short general summary of 
the results obtained from these four years’ experiments, 
and to deduce such conclusions as appear to be probable 
ones, and which may possibly assist in the elaboration 
of further experiments. 
The methods adopted were those in use by the 
English workers participating in the International 
Fishery Investigations. The mark consisted of a hard 
*<¢ Ann. Repts. Lancashire Sea-Fish. Laby.” for the years 1904 
to 1908, Liverpool, 1905-1909. 
