A STUDY ON TROUT AND YOUNG SALMON. 293 



In these small watercourses the spent fish of course never 

 remain long. However I have considered it too slow work in such 

 localities, to catch so large numbers of individuals, that their 

 introduction in the tables would be in any marked degree illu- 

 strative of the relative abundance of mature and immature 

 fishes. 



On the whole it seems to be a peculiarity of the 

 trout, at least in the rivers examined by me, that the mature 

 fishes do not remain long in the river either before or after 

 spawning. They run quickly up the river or watercourse, spawn 

 and return to the sea. In my opinion this fact is rendered 

 evident if on one hand we remember, what I have remarked 

 above on the scarcity of large trout during summer in the Orkla 

 and the Gula, and on the other hand note, that during late autumn, 

 October and November, I have often in my seines in the sea 

 caught recently-spent trout. 



Thus it will easily be understood that the tables from the 

 rivers are fallacious as regards the numeric relation between 

 mature and immature trout. 



If any of the materials collected by me might be supposed 

 to illustrate this relation, it would be table VII col. I Beitstad- 

 fiord. May 1900. 



This table may be considered as illustrative of the usual 

 catches of trout in the sea at this season. Later on, during 

 summer, the upper group will move down, as the fish grow. 

 Even here however, as is usual in the tables, the larger fish 

 (above 30 cm.) are few, compared to the younger group. 



A careful examination of the measurements of about 500 

 trout, which some years ago were effected by Mr. Simonnæs 

 in western Norway (vide report of the Inspector of Fresh-water 

 fisheries 1895 — 96) shows the same result as my tables. 



This relation between the numbers of larger and smaller 

 trout must evidently thus be of general value, and clearly the 



