On 
SUMMARY AND GENERAL REPORT. 
The work of the Laboratory during the past year has been 
directed mainly to plankton, but the results are far from being 
ready. The following report, as will be seen, refers to other 
investigations, which have progressed sufficiently to warrant 
publication. 
An opportunity was taken during a voyage of the ‘‘ Evadne” 
to test an otter trawl, and although the results are not quite 
comparable with those obtained with the use of the beam trawl, 
they are interesting enough to record. 
The herring investigations during the past year were 
extended, and samples were examined by Mr. Storrow and 
Mrs. Cowan from the west of Ireland, the Irish Sea and the 
Firth of Clyde, as well as from the North Sea and the waters 
about the north-west of Ireland and the north of Scotland. 
Altogether, 25 samples, comprising some 4,700 herrings, have 
been examined. 
The age composition of the shoals is much the same as in 
the previous year, if allowance be made for the fish being a 
year older. Further evidence has been obtained which supports 
the idea that abnormal numbers of young fish joined the spring 
spawning shoals of 1921. The Firth of Clyde shoals differ from 
other shoals in having their greatest numbers belonging to the 
1917 year-class, and an abundance of the same year-class was 
indicated in the waters to the west of the Shetlands by a sample 
obtained in June of this year. 
The failure of the fishery is held to be due chiefly to a 
shortage of fish with three winter rings, and this shortage in 
summer shoals was intensified by the young fish joining spring 
spawning shoals in 1921. The Yarmouth grounds received 
