Su m mary. 



In the years 1894 — 95, with the aid of a grant from the Stor- 

 thing, experiments were made at the Bergen Biological Station in 

 hatching the spawn of salmon and sea-trout in salt water and in 

 brackish water. These vere undertaken principally on account of 

 the strong assertions on the part of the the coast fishermen, that 

 there are salmon which spawn in the sea, where, therefore, develop- 

 ment ought also to take place. 



Both English and Norwegian investigators, who have interested 

 themselves in the matter, have, however, come to the conclusion 

 that ordinary sea-water has a deleterious effect upon salmon spawn. 

 Nor can any change in this conclusion be authorized by the experi- 

 ments made at the Biological Station. It has on the contrary been 

 proved that in water containing between 20 and 30 per mille salt 

 ( at 15° C), not a single egg reaches development, whether the* 

 spawn be fertilized in salt water or in fresh. 



During attempts to fertilize salmon spawn in sea-water (about. 

 32 %o salt), one peculiarity was observed which is so striking, that 

 a glance at the spawn is sufficient to determine whether it has. 

 been fertilized in sea-water or in fresh. While the spawn fertilized 

 in fresh water immediately swelled out, aud became quite hard, 

 the spawn fertilized in salt water remained fairly soft, and the eggs, 

 in consequence, assumed irregular shapes, owing to mutual pressure. 

 After lying for several days in sea water, the roe fertilized in salt 

 water also swelled out, and became quite hard to the touch. The 

 same phenomena have been observed in the case of the spawn of 

 sea-trout. Eveu after the fertilization of the trout spawn in slightly 



