328 Part I[I.—Twenty-fourth Annual Report 
They formed a compact group (Pl. XVII.) ranging fram 148mm. to 
192mm. 5132 to 7,°, inches), the modal size was 167mm. (6,°, inches), the 
mean was 170mm., and the computed average 168-8mm., or 61% inches. 
These herrings were obviously the same series as those taken on 30th 
May, that is, herrings in the fourth year, and thus, in all probability, 
spring herrings somewhat over three years of age. 
The increment of length in the 29 days is, on comparison of the 
modes, 7mm. to 8mm., on the means 6mm., and on the averages 6°9mm., 
ov a little over inch. The rate per day, taking the increase at 7mm., 
was 0:24]1mm., and per month about 7-5mm., and this in the best period 
for growth. If asimilar rate is assumed for July and August, the 
increase in the three best months of the year would amount to a little 
over 22mm. (7 inch), which contrasts with the growth of the whiting, as 
indicated on a former page. 
If the group taken on 13th June is contrasted with the small herrings 
got in the Bay of Nigg, Aberdeen, on the 19th June, referred to 
previously, whose average was about 60mm., and which were also judged 
to be autumn herrings, the growth in the two years is seen to amount 
to about 80mm. (3,3, inches). If, moreover, the herrings taken in 
Aberdeen Bay on 30th May are contrasted with those taken at the 
beginning of the same month (and year) in the Firth of Forth (both 
being judged to be spring herrings, and the latter about thirteen months 
younger), the differences are as follows:—On the modes 46mm., on the 
means 47°5mm., and on the computed averages 48:°5mm., showing a 
mean difference of about 47mm. (17 inches), or at the rate for the whole 
period of 385 days of about °122mm. per day, or 3°7mm. per month. On 
5th July, 1901, eight herrings were taken in Aberdeen Bay, measuring 
from 140mm. to 164mm. The modal size was 140mm., the mean 
150mm., and the computed average was 149-2mm., or 52 inches. They 
belonged, no doubt, to the same series as that of 13th June. 
Some good collections of herrings were obtained in the Dornoch Firth. 
On 9th February 8 ranged from 104mm. to 122mm., the mode and the 
mean were 113mm., and the average was 112°'4mm., or 43 inches. The 
position of these is in February of the third year, i.e., nearly two years 
old, if spring herrings, as they probably are. 
Sixteen obtamed on 31st March ranged from 106mm. to 136mm. 
(4,3; to 53 inches), the mode being 112mm., the mean 121mm., and the 
computed average 117-6mm., or 42 inches. No doubt they represent 
the same series as in February, and are about two years of age. 
Several collections were obtained in November. On 5th November, 
1900, in from 7 to 10 fathoms, 4784 herrings were taken in a haul of 
14 hours’ duration, of which 601 were measured. The smallest noted 
was 73mm., and the largest 206mm., and the great maiority ranged 
about llem. to 1ll'5em. The first series is not fully represented, 
probably because of the escape from the net of the smaller fishes. It 
extended from 73mm. to about 97mm.; it might be 99mm.; the mean 
was 85mm., and the computed average 90mm., but the herrings repre- 
sent only part of a series (in their second year). The 2mm. arrangement 
of the measurements at this place is as follows :— 
86-7 88-9 90-1 92-3 94-5 96-7 98-9 100-1 102-3 104-5 106-7 108-9 
5 7 7 9 8 3 5 7 6 7 19 36 
The next series is taken as extending from 98mm. to 141mm. 
(832 to 5,% inches), but it may end about 13cm. or 13‘5cm. The 
arrangement of the 2mm. measurements is as follows:— 
124-5 126-7 128-9 130-1 1382-3 134-5 136-7 138-9 140-1 142-3 144-5 
21 16 8 2 4 3 1 2 1 - 2 
