— 132 — 



when the growth in the scales is very small, and these on the whole show signs of age. 

 When the coalfish has exceeded the age of 14—15 years, the age can hardly be deter- 

 mined any longer to within l year on account of the small growth in the scales. The 

 regular growth can be seen from Damas' drawings, fig. 52, where the scales are figured 

 in proportion to the size of the fish and the winter rings are represented by continu- 

 ous lines. 



From a series of measurements of specimens from various localities along the coast 

 from southern to northern Norway it appears,, that the amount of growth decreases from 

 south to north and with the distance from the fjords. As example of this we may state 

 that the increase in growth in the course of the second year amounted 



on the Skager Rak coast to 16 cm. 



at Hvidingsö near Stavanger to. ... 15 — 



- Bergen to 15 — 



on the Romsdal coast to 10 — 



at Trondhjem to ; 11 — 



- Lofoten to . . . 8 — 



This feature in the rate of growth explains why it happens, that there is an autumn 

 fishery of the o-group on the Skager Rak coast of Norway, whereas this year-group 

 further north is too small to be the object of a fishery. In the southern localities where 

 the growth is large, the different year-groups are so marked that they can be easily 

 distinguished. The people even give them separate names. Further north the groups 

 run into one another more. Damas expresses the interesting view that this difference in 

 growth in the different localities would perhaps make it possible to follow the migrations 

 of the coalfish. Since, namely, the growth of the scales stands in relation to the growth 

 of the fish, the scales thus characterize the types of the different localities, and he con- 

 cludes therefore that it would be possible to detect the arrival of strange types from the 

 north or the south. 



Damas' paper contains some tables showing the composition of some hauls in regard 

 to age, such as the accompanying fig. 53, which represents a haul in July 1907 at 

 Romsdal. The catch amounted to 654 specimens. Groups from the 3rd— 8th year are 

 included, the weakly represented year-groups are excluded. The sample presumably 

 includes the younger spawning year-groups and most become mature first in the fourth year. 



A second haul from the neighbourhood of Romsdal in the winter (April) of 1907 

 includes fish from 59—100 cm. in length and these were distributed over the different 

 year-groups as follows: 



6th year-group 6 specimens, between 62 — 73 cm. long, average 66.5 cm. 



7. _ 15 _ _ 59-69 — — — 67 — 



8- — 31 — — 63-73 - - — 69.7 - 



9- — 21 — — 65—77 — — — 71-1 — 

 10- — 30 — — 70-87 - — — 75-s — 



