MG Girne 
we remember that three quarters of the whole stock of skrei lie within a size field of only 
20 cm. in extent. In 1913, the averages both for the whole sample and for the separate 
groups approach very nearly the average for all years. In 1902, 1903 and 1905, the 
size of the skrei was below, in 1906 and 1907 above the average. The individual groups 
likewise exhibit great variation from year to year. Thus the group 65—69 cm. was repre- 
sented in 1903 by 19.1 %, in 1907 only 1.6 %. In 1906 and 1907, the total number of 
individuals under 70 cm. was less than 3%, in 1902 over 30, and in 1903 over 40%. A 
glance at the figure will show, that the years 1902, 1903, 1905 and 1913 have their majo- 
he — Östlofoten. 
u Vestlofoten 
me Flosthavet 
ES SESS GSS 85 75 OS Se 
99 69 79 89 79 109 119 
Fig. 59. Average composition in point of size of all samples from the three distriets in 1913. 
rity to the left, 1906 and 1907 to the right of the central group, 75—79 em., within which 
the average for all years together is situate. In 1902 and 1903 the individuals are widely 
distributed throughout a number of groups, whereas in 1906 and 1907 we find them 
highly concentrated about a few groups, with especially high percentages, and some 
greatly dominating sizes. 
Throughout the whole of the period 1902—1913, there seems to have been some definite 
process at work; a regular movement of the centre of size. Thus we find that from 1902 
to 1903 the size decreases, the average falling from 74.9 to 71.8. An increase is then 
apparent, from 1903 to 1907, the average rising from 71.8 to 81.1, and finally, from 1907 
to 1913, again a decrease. We shall in the following frequently have occasion to refer 
to these very important fluctuations in the size of the skrei. 
