of the Fishery Board for Scotland. 337 
1 1 III. 
pes 5 Computed. 
Age. Year.| Range. | Mean. Range. {Observed 
Min. Max. | Mean. 
1 45-76 62 
2 (1) | 118-121 117 94-139 112 110 122 116 
3 (2) | 156-164 160 142-186 as 158 170 164 
4 (3) | 190-198 194 177-228 se 206 218 212 
5 (4) | 217-225 229 218-265 cs 254 266 260 
6 (5) | 237-245 241 240-257 = 302 314 308 
Column I, shows Jenkins’ results, Column IT. shows my own results, 
and Column IIT. shows the results obtained by Masterman, and the 
size at the later stages, computed at the mean rate of increase of 4mm. 
to 5mm. It will be observed that my results and those of Jenkins 
agree remarkably well, when a year is added to the age he assigns to 
his various series. 
In the later work of Masterman and M‘Intosh (17a) it is suggested 
that 3 inches (76mm.) and 5 inches (127mm.) represent a rough 
average of the size of the herring when one year and two years of age 
respectively ; and that sexual maturity is attained when it is between 
8 and 9 inches (203—228mm.) in length and probably three years of age. 
This, however, involves a more rapid growth than the facts warrant, and 
is not consistent with the results of Masterman’s own earlier paper. 
The earlier authors referred to at the beginning of this paper asa 
rule under-estimated the rate of growth of the herring. The most 
correct are those of Malm, Sars and Nilsson. It is interesting to 
observe that the estimate of the fishermen of Bohuslin, Sweden, as 
given by Nilsson, is accurate; and that the estimates of the Scottish 
fishermen (three or seven years) was much nearer the truth than those 
of the naturalists. 
The elucidation of this question of the growth of the herring has an 
important bearing on several fishery problems. Compared with most 
fishes caught by lines or trawls, it is clear that the herring, caught by 
drift-nets, has a great advantage, inasmuch as no immature herrings 
ave caught in this way, no less than four generations of undersized or 
immature herrings escaping through the meshes. 
It may also help to explain such problems as the presence every 
summer for a period of years of large herrings in the deep water of 
Upper Lochfyne, and their absence for a period of years. It is quite 
possible that these herrings belong to one and the same shoal, which has 
accustomed itself to the route of migration and the locality, and which 
is ultimately fished out or destroyed. It may also serve to explain the 
presence in the loch of small herrings in autumn and winter without 
supposing that they were spawned there. Such little herrings are one 
year old and more, and could therefore easily make their way into the 
loch from the spawning grounds in the outer part of the Clyde. 
