294 KNUT DAHL. 



size of the great proportion of the trout, which can be caught 

 in our waters, is smaller than the size at which the majority of 

 the individuals of the species attain sexual maturity. 



Whether this fact is a correct expression of the really 

 existing relations in the natural economy of the species, I am 

 of course unable in any satisfactory way to illustrate. 



However I wish to draw attention to the fact, that the trout, 

 having reached the sizes peculiar to the mature stages, becomes 

 much more roving and wandering, partly resorting to localities 

 where our ordinary fishing implements are insufficient. The 

 labelling experiments effected by Mr. Landmark in one of our 

 western fiords seem indeed to show that the trout do not wander 

 much. However if we consider, that I have procured large 

 trout from the mackerel driftnets as far as 26 miles off Oksö 

 in the Scagerrack, and further, that nearly all mackerel fisher- 

 men from the Scagerrack and Kattegat state that trout are caught 

 in their driftnets miles at sea, it is at all events evident, that 

 some trout must wander considerable distances away from the 

 rivers or brooks where they were reared. Thus knowing that 

 larger trout may occur as pelagic fishes many miles from land 

 in the open ocean, we cannot possibly expect them to be plenti- 

 full in the fiords at the same time of the year. 



Further conclusions as to the progress of reproduction and 

 the economy of the fish I do not consider justified by the 

 material at hand. I can only state, that the trout in all the 

 waters investigated by me is 'exceedingly numerous. In this 

 connection I also wish to draw attention to the fact, that the 

 economy of the trout of the sea cannot be considered to be 

 dependant solely on the reproduction of this form. 



In my opinion the freshwater forms of the trout also con- 

 tribute to the abundance of trout in the sea. Thus, trout con- 

 tinually descend from the fresh waters to the sea, trout which 

 are not direct descendants of the trout form of the sea, but belong 



