330 Part LIl—Twenty-fourth Annual Report 
On 25th December, 1901, a collection of 87 herrings was obtained at 
Burghead Bay, in fr om 1s to 18 fathoms. ‘Two series were present, the 
ae consisting of 19 fish, ranging from 139mm. to 183mm. (54 to 135 
inches) the mean being Velo. and the average 162°4mm., or 68 
inches. These are apparently autumn herrings over three years of age. 
The second series consisted of 68 fish, ranging from 186mm. to 
223mm. (73%, to 82 inches); the modal size was about 198mm., the 
4 
mean 2()4: ifine: and the average 201mm., or 742 inches. These also 
were autumn herrings over four years of age. : 
The numbers are not large, but comparison of the sizes of the two 
groups shows an increment in the year of 59°6mm., or a little over 1} 
inches. 
On Ist April, 1904, off Findhorn, in the same neighbourhood, 497 
herrings were obtained, the depth of the water in this case being from 
30 to 32 fathoms. They were the largest herrings got in any of the 
collections by means of the otter-trawl. (Plate X VIII.) 
Eleven of them belonged to one series, and ranged from 123mm, to 
169mm., the mean size being 143mm., and the average computed 
150°8mm., or about 512 inches. 
IT6 
The ae group Coneieeed of 478 herrings, ranging from 177mm. to 
228mm. (7 to 9 inches), but the series might stop about 223mm. The 
maédall size was about 200mm., the mean was 202‘5mm , and the com- 
puted average was 203-2mm, ‘These herringe were therefore about 
8 inches long, and they were spring herrings, as their position in the 
synthetic table shows, a little over four years of age. 
Another collection from the Moray Firth was obtained in the 
Cromarty Firth on lst June 1901, and of the 70 taken, 66 measured 
from 111mm. to 155mm. (43 to 63 inches); the mode was 135mm. (5;°5 
inches), the mean was 133mm, and the computed average 129°7mm., or 
5% inches. 
These were autumn herrings approaching their third year of age. 
The next largest herrings measured by me consisted of a “ cran” of 
spring herrings, caught by drift-net, in the ordinary way, on 16th 
February 1904, in the neighbourhood of the Isle of May, at the mouth 
of the Firth of Forth, and landed at Anstruther. They were actually 
spawning, and it was thus a simple matter to separate the sexes and 
measure them apart, a task in which Mr. William Keir, the Fishery 
Officer of the district, was good enough to assist me. The measurements 
will be found in Table IIT., and the curves on Plate XIX. 
A glance at the peculiar curve is enough to show that the herrings 
(lo not form a homogeneous group. The range is too great for one 
series, viz.,over 70mm. (2? inches); the oblique line on the synthetic chart 
connecting the extreme limits of the spring herrings of various ages, 
when prolonged, goes through the middle of the collective measure- 
ments; and consideration of the millimetre table and the curves shows 
that two groups are present. The males and females were measured 
separately in two lots each, or four in all, and when curves are made 
of these separate measurements, they all agree in having two cusps, or 
modes, with a depression at about 25cm. The following Table shows 
the grouping in each of the four measurements, in ‘5em., and also the 
arrangement of the 2mm. grouping at the critical place:— 
(TABLE. 
