eo 
numerous investigations as to the age of the Gadoid species, carried out with the greatest 
energy and skill by Dr. Damas, are in particular to be regarded as of the greatest import- 
ance. 
The investigations carried out by the International Commission terminated abruptly 
with the publication of the report. This unexpected conclusion of the work I then re- 
garded, and must still consider, as highly to be regretted. The results attained had opened 
up what promised to be a most fertile field for continued methodical study of one at 
least of the principal points in connection with the fluctuations of the fishery, viz. the 
varying composition of the actual stock. It was moreover evident that such studies 
could only be carried out by means of samples collected throughout a series of years, 
and treated with a view to determining the composition of the stock in point of age. 
I found it impossible, however, to obtain the necessary support in my endeavours to 
bring about the promotion of an international organisation for the study of the various 
races of cod and herring. I nevertheless continued to prosecute my own researches 
on the subject as far as opportunity permitted, partly by the collection, on a smaller 
scale, of material for the study of fluctuations in the stock of cod in Norwegian coastal 
waters, partly by organising the extensive collection of herring samples, embracing the 
principal varieties known in northern European waters. The former of these two projects 
has been greatly furthered by the Norwegian fishery investigations alone; as to the 
latter, the International Council has here furnished considerable means and valuable 
assistance. 
As regards the investigations concerning the cod, during which I have had assistance 
from Mr. Eınar KoEFOED and Mr. Oscar SunD, nothing has been published since 
the report of the International Commission; I therefore purpose to give, in the following 
chapters, a survey of such results as have hitherto been attained. 
With regard to the herring investigations, on the other hand, various publications 
have appeared, some of these being by my Assistant, Mr. Ervar LEA, while some again 
are largely due to the valuable aid which he and others have rendered me during the 
past years. 
Some doubt or misunderstanding having arisen in various quarters as to the methods 
adopted in the herring investigations*) Mr. LEA has subjected the methods in question 
to further careful examination in several exhaustive treatises**). The result of these 
has been to greatly strengthen the conviction that a study of the scales of the herring 
enables us not only to determine the age of the fish, but also to calculate its size at each 
of the different periods of growth, in accordance with the idea which from the first formed 
the basis of the method, viz. that the structure of the scale is in itself a record of the 
growth history of the fish. 
In addition to this, my Assistants, Dr. K. Dant, Paut BrerKan and others, and 
*) SCHNEIDER, Guipo, Ueber die Altersbestimmungén bei Heringen nach den Zuwachszonen 
der Schuppen. Svenska Hydrograf-biologiska komm. Skrifter, 1910. 
Lez, Rosa M., An Investigation into the methods of growth determination in fishes. Publ. 
de Circ. No. 63, 1912. 
**) On the methods used in the Herring Investigations. Publ. de Circ. No. 53, 1910. 
A Study of the Growth of Herrings. Publ. de Circ. No. 61, 1911. 
Further Studies concerning the Methods of Calculating the Growth of Herrings. Publ. de Cir- 
constance, Nr. 66, 1913. 
