— 184 — 
Quantity of roe No. of hectolitres ofroe . 
Year (in 1,000 hectolitres) per 1,000 fish 
WOO Gyre RAP 25.4 1.43 
NOT 22.0 1.71 
ODA 19,9) 1.36 
OOS ua te 20.5 1.80 
OTUs Seated ta 20.1 1.87 
LIENS. ae 17.8 1.16 
From the figures here given, we arrive at the remarkable result that the two years 
1903 and 1904, which produced (judging from the subsequent yield of the Finmark and 
Lofoten fisheries) the greatest quantities of cod known in recent times, were the very 
years in which the quantity of Lofoten roe was at its least. As will be seen later on, 
this can scarcely be accidental; many observations would even seem to indicate that the 
tichest year classes may be spawned in years when the quantity of roe taken is small (vide 
Chapter VI). We cannot, however, therefore conclude that the years when the spawning 
is at its lowest are those which produce the greatest number of fish, and although much 
would appear to support such a view, no investigations have yet been made which can 
satisfactorily demonstrate its truth. Be this as it may, it is in any case entirely unjusti- 
fiable to assume that the years exhibiting the richest yield of roe are those which produce 
the greatest quantity of fish. 
It is, moreover, equally unwarrantable, in view of actual experience, to fix the age 
of the Lofoten skrei at 7 years and that of the Finmark cod at 5. The Lofoten fish con- 
sist, as we have seen in the previous chapters, mainly of individuals from 7—11 years 
old. Within these limits, the age of the fish varies considerably from year to year, now 8 
year fish, now 9, and at other times 10 year old individuals being in the majority. If, 
therefore, it is desired to compare the quantity of roe taken in the Lofoten fishery during 
the birth year of a certain class, with the subsequent yield of grown fish, with the object 
of discovering the relation between the amount of roe and size of the resulting stock, 
then the relative position of the curves must be adjusted, not in accordance with a single 
permanently valid formula, but according to the actual composition in pomt of age 
of the Lofoten stock in each separate instance. With regard to the Finmark fish, the 
case is here even more complicated. As we have seen in the foregoing chapters, the 
stock in these waters consists of two different kinds of fish, the skrei and the loddefisk. 
The skrei here vary with regard to age in the same manner as in the case of the Lofoten 
stock; the loddefisk include several year classes, mainly those from 5 to 7 years inclusive, 
the relative value of these year classes again varying from year to year. Thus there 
is very little similarity apparent between the curves shown in Fig. 113; the conditions 
are too complicated to permit of any so schematic illustration. The great secret which 
has been the problem of the fluctuations in the quantitative yield of the fishery is of an 
entirely different character to that supposed by HELLAND-HANSEN and NANSEN. 
Variation in quality of the fish. 
It might nevertheless be supposed that the variations apparent in the quality of the fish 
may be due to the causes and regulated by the laws to which Hettanp-Hansen and 
