KNUT DAHL. 



a continually sinking course, while the curve representing the 

 yield of the sea must rise. 



It must here, however, be remarked, that the number of 

 rivers which are taken account of in the statistical tables, has 

 gradually been increased without the total yield of the rivers 

 presenting a corresponding rise. 



The number of the rivers counted in the statistical tables was: 



in 1880- 



-1883 



55 rivers 



- 1884- 



-1886 



79 „ 



- 1887- 



-1890 



89 „ 



- 1891- 



-1894 



• 93 „ 



- 1895- 



-1896 



108 „ 



- 1897- 



-1898 



122 „ 



If however, we, examine the quality of the catches from the 

 rivers, we find, that the main ones are included in the returns 

 for 1886. This is in good harmony with the rise of the curve 

 during this period. (Vide fig. 3, 1). 



The rivers, added to the statistical returns after 1886, will 

 upon examination be found to be less important. 



If we further remember that year by year more and more rivers 

 have been let for sporting purposes and their yield in salmon- 

 flesh consequently lowered, it must be taken as granted that 

 the curve of the rivers as represented in fig. 3, is reliable in 

 the same degree as the other curves based on our statistics. 

 At all events it is obvious that there is no reciprocal proportion 

 between the yield of the fisheries in the sea and those in the 

 rivers. 



If the curves of the Trondhjem district are examined (fig.s 

 5 and 6) the same facts will be observed. Far from presenting 

 any decrease in the yield, the rivers on the contrary show a 

 large increase, while the yield of the sea has constantly been 

 increasing. 



