20 — 



As the occurrence of the eggs and larvae in some portions in the fiords deeper 

 than 20 metres were not investigated, the vertical distributions of the said organisms 

 is not fully shown by this table. However, as I shall later on show, the probability is, 

 that the main body of eggs and fry in these waters are distributed in water of a 

 specific gravity of 1-021, as we also see in the above table. 



The relative distribution of eggs and fry is according to the above table, absolutely 

 the same. The larvae if anything seem to be relatively more numerous than the eggs 

 in the upper water layers. But a safe comparison is impossible, the catches consisting 

 not only of eggs, which have risen to their true level, but also of eggs which after 

 spawning are still rising through the water and consequently are distributed in the 

 whole water column. Besides, the current can suck up both eggs and larvae out of 

 the level where they would float in still water. 



Direct experiment is therefore the only way of ascertaining the true specific gravity 

 of eggs and larvae. 



Such experiment was made by me and the manager of the Fl0devigen hatchery in 

 1905. Eggs and larvae from the hatchery were placed in glass vessels containing water 

 of different specific gravity. The observations gave the following results. 



Apparently in these southern waters practically all cod eggs and larvae will float 

 in still water of an absolute specific gravity of 1-021. This is also confirmed by the 

 experience gained at the hatchery during all its working years. If the specific gravity 

 of tho water employed by the hatching sinks below 1-021 all cod eggs and larvae 

 cannot be kept floating in the hatching boxes. 



The normal vertical distribution of eggs and larvae varies in two ways. 

 We can recognise a variation dependant on local difference and a variation parallel to 

 hydrographical changes in the water layers. 



As an example of the first kind the following table is instructive. 



Sandnes-Fjord ' 31. HI 1905 st. I and n 



In each depth 2 hauls. In 20 m. only one haul, the depth at st. I being only 12 m. 



