29Ô KNUT DAHL. 



during winter. Although I am not in a position to determine 

 definitely their places of resort in the sea during the winter 

 months, I believe their habitat to be nearly the same as 

 during summer. The only time of the year, when I have 

 not been able to catch them along the shores, where they live 

 in summer, is the space of time between the latter end of No- 

 vember and the end of February; but during this time I have 

 not made many hauls. As early as in the first days of March, 

 I have nearly every year been able to procure, trout, as well 

 singly, as on some occasions in large quantities, in single hauls. 

 These fish have been of the same size as the emigrating „isfisk" 

 of spring, but have been fat. 



As I have mentioned above, these trout scarcely grow at all 

 during winter. Also the trout kept in aquaria at my station have 

 refused food during winter, reposing quietly on the bottom or 

 among stones. These facts have conveyed to me the notion, 

 that the trout of these sizes (between 20 and 30 cm.) only eat 

 very little during winter, keep quiet in a sort of half-torpor, the 

 reduced processes of life being maintained on the fat accumu- 

 lated during summer. 



The tables V — VII very plainly show the growth of the 

 fish from the moment it leaves the river for the first time 

 10—20 cm. long, until it returns to the river in autumn, 

 hibernates, and re-emigrates. If we observe the progress of 

 growth as regards the fish of the Orkla and compare the first 

 column of tables V and VI, it transpires, that the youngest 

 emigrants of spring, during summer have grown from 10 — 20 

 cm. to a length varying from 10 or. 20 to some 30 cm. When 

 these fishes during the following spring re-emigrate, their size 

 is nearly unaltered, as will easily be observed by comparing 

 table VI, first and last column. 



As regards the Gula, comparison of column 2 and 5 table V 

 will show the same progress of growth. 



