336 Part TI1.—Twenty-fourth Annual Report 
Growth in length, however, as with most fishes, is somewhat more 
rapid in the early stages, and diminishes with age, at first very slowly, 
and then on the occurrence of sexual maturity with great and marked 
rapidity. 
The following gives the main features of the growth of the herring, 
according to this investigation :— 
Approximate Age. Length. Preset ars 
Mm. Inches. Mm. Inches. 
Year, es : : : : ; 60°5 23 - - 
Ay NOCHE : . ¢ : é 113 45 52 245 
5 Sea eae tn ee OW Oe ane 61 AT 1g 
4 | 200 i 41 18 
5 238 93 38 1k 
6 | Bay 103 19 3 
The herring, both male and female, appears to attain the mature 
condition, and to reproduce for the first time, when it is five years of 
age. 
“Tf the same rate of growth as is indicated above between the fifth and 
sixth years be assumed to continue during the next few years, the 
approximate average sizes of older herrings would be as follows:—7 
years, 276mm. (101 inches); 8 years, 295mm. (113 inches); 9 years, 
314mm. (122 inches); 10 years, 333mm. (131 inches). It is certain, 
however, that the growth in the later series of larger herrings is not 
nearly so rapid as this, and herrings over 12 inches are probably more 
than ten years old. The larger herrings of 13 to 15 inches, such as are 
referred to on a former page, must be very old; the latter probably 
from fifteen to twenty years. 
It may be of interest now to compare briefly the results as stated 
above and those obtained by Jenkins and Masterman. The research of 
the former, as previously mentioned, was made on the otoliths of spring 
herrings of the Baltic, and the precise age could not, therefore, be deter- 
mined with certainty, not within several months. The research of 
Masterman was on both spring and autumn herrings at St. Andrews, 
but was confined to specimens taken in tow-nets—to larval and _post- 
larval forms, and to small numbers of young herrings obtained in the 
same way—and so far as his research was carried it agrees well with 
my own. He did not attempt to deal with the growth of the older 
series of herrings, except in a few cases, but made certain calculations 
as to the rate of growth per month. In the following Table I give a 
summary of the results of Jenkins (as amended by the intercalation of 
a year, so as to make his annual series a year older than he represents 
them), and also of the results of Masterman on the spring herring, as 
far as they go, and the approximate sizes of the older series as calculated 
on the basis he gives, viz., a growth of from 4mm. to 5mm. per month. 
The latter is quite accurate for the early stages, but it is rather wide of 
the mark for the older herrings, owing to the diminution of the rate of 
growth with age that actually takes place. 
