SEHA-FISHERTES LABORATORY. 1 27 
PLAICH MEASUREMENTS MADE DURING 1908. 
By Jas. JornstTone. 
The following tables relate to the individual 
measurements of 21,000 plaice made during the year 
1908, mainly during the months of July to December. 
The measurements were made on board the s.s. ‘“ James 
Fletcher,’ and on board the sailing cutters stationed at 
Fleetwood and New Brighton. Measuring boards, made 
after the pattern suggested by Professor D’Arcy W. 
Thompson, were used on the “James Fletcher.’ These 
boards are provided with cork inlaid between strips of 
celluloid, the latter marking centimetre divisions. Hach 
fish 1s laid on the scale, and a brass (“* lacemaker’s ”) pin 
is stuck into the cork strip opposite to the centimetre 
division on which the tail of the fish lies. By this method 
the fish are measured rapidly and exactly, and it is not 
necessary to use a notebook to record the numbers. When 
the catch is measured the board is taken into the 
laboratory and read. For some reason or other, the 
Bailiffs on the sailing cutters prefer to use a notebook 
ruled in the usual way and with a centimetre scale written 
along the left-hand margins. <A tick is put opposite the 
number called out as each fish is measured. 
The method adopted in the International Fishery 
Investigations is also adopted here—that is, no fractions 
of a centimetre are recorded, and all fish measuring 
between (say) 15 and 19°9 cents. are regarded as measuring 
15 cents. It is necessary to add 0°5 cm. to averages 
deduced from the measurements. 
Table I contains the measurements of plaice caught 
off the Mersey estuary in a trawl-net of 6-inch mesh, and 
