4 
PAUL BJERKAN: THE YOUNG HERRING 
[Rep. Norw. Fish. Ill 
The material thus secured has been given to me by Dr. Hjort 
for examination. The preliminary results of this investigation have 
been published with a map by Hjort in 1914 (1. c.). As, however, 
the aim of his work was by far too wide to allow of a thorough 
consideration of the special features displayed by the material, I find 
it to be of interest for the further study of the question to publish 
the results in details, in each case with reference to the available ma¬ 
terial. 
As might be understood by those who have worked with similar 
questions, it is a difficult task in the open sea to secure a suitable 
material in order to solve such a problem. As it is, the material is 
not very extensive and further investigations will perhaps give a better 
material and more definite results, but as a first attempt, the investi¬ 
gations might be of some use by indicating the best course for further 
study. 
A few of the samples were not available for my examination, but 
in most cases I could then find accounts of the material in the journal 
of the cruises and, in some instances, measurements of a number of 
individuals. In this paper I will confine myself to the treatment of the 
first three age-groups, — herrings which live in their first, second or 
third summer, and are therefore said to belong to the 0-, I- and Il-group. 
The scales of these herrings have then either none or one or two 
winterings respectively. In the supplementary table I I have shown the 
results of the measurements of the herrings belonging to these three 
age groups. The separation of the age groups as shown in table I is 
largely made on the principles shown by C. G. Joh. Petersen, who 
found that the frequencies of the length-groups displayed the different 
age-groups. As shown by later investigations this holds good for the 
younger year-classes. In some cases I have made use of the scales to 
make sure about the age of the herrings. The determination of the 
age by the scales could not be universally applied, owing to the fact 
that many of the herring in the samples had lost their scales. This 
is often found in young herrings, which have been somewhat roughly 
handled, as is the case in most of the trawl catches. In table I are 
found records of date of capture, locality, depth of the station and gear 
used in taking the sample. From the map can be seen if other imple- 
