Re 
however, not very great. The smallest of these full-grown herrings weigh about 150 gr. 
or somewhat over 6 per kg., the largest about 250 gr. or 4 per kg. 
It is very interesting to compare these 
statements as to the average size of the spring 
herring during late years with the mean va- 
lues found for the samples scientifically ex- 
amined, both as regards the samples as a 
whole and especially for the individuals of 
the 1904 year class. A comparison on 
these lines is given in Fig. 26. 
On the extreme left is shown a curve (1) 
for the average volume of the herring (in 
cubic cm.) for the years 1907—1913*). It 
will be seen that the volume of the fish sank 
in the years 1907—1910, rising again to its 
highest figure in 1913. Farther to the right 
will be found the average weights for the 
samples (2) and the year class 1904 (3) in the years 1910—1913. These exhibit a rise 
which is perfectly parallel with the curve to the left. 
Fig. 27 shows the average length for all individuals in the samples (1) and in the 
1904 year class during the years 1910—1913 (see also Fig. 15). 
In the case of the spring herring also, the statements as to the fishermen’s hauls 
agree entirely with the figures for the samples examined. 
1910 11 12 13 1910 11 12 13 
Fig. 27. Average length (cm.) of all individuals 
in the sample from 1910—1913 (1) and of fish 
of the 1904 year class in the same (2). 
Fluctuations in the yield of the spring herring fishery. 
The fishery statistics give the following figures expressing the yield of the spring 
herring fishery for the years 1904—1913 in hectolitres: 
1904.... 528,000 1909.... 772,000 
1905.... 633,000 1910.... 982,000 
1906.... 775,000 1911.... 1.054,000 
1907.... 979,000 1912.... 937,000 
1908.... 625,000 1913... . 1.500,000 
These columns reveal a distinct increase for the years 1909—1915, and it would 
also here appear to be evident that the yield of the fishery has been exceptionally rich 
from the time when the year class 1904 began to play a prominent part. We thus find, 
bothin the fat herring fishery and that of the spring fish, similar evidences of an increase 
dating from the time when the year class 1904 began to make their presence felt among 
the stock. This is very distinctly noticeable in a graphical representation of the state- 
ments of the fishery statistics, both for the fat herring and the spring herring yields, 
Fig. 28. 
We cannot, however, in this case attach the fullest value to these statistics, as they 
indicate the amount of the yield in hectolitres, and not in number of fish, and, owing 
*) These figures have been obtained by calculating the average of the statements as to how 
many fish were reckoned per barrel measure in the different years. 
6 
