70 JOHAN HJORT- M.-N. Kl. 



exist (at the present time), the sahne contents are, throughout, very 

 great, exceeding 3 per cent.« The influence of the saHneness on all 

 these species is, possibly, mostl}- due to its action on the ivandering 

 pelagic fry, and we thus see in this, a new proof of the great depen- 

 dence of the Plankton on the ocean currents. 



In his reports for the years 1866 to 1869, Sars gives an account of 

 the habits of the Cod during its first period of existence. He reports 

 that the fry, when it leaves the Çi^^, leads an aimless life, as it drifts 

 about on the surface of the sea, and only has slight powers of motion. 

 When it attains a length of about 40 to 50 mm., it retires from the 

 surface to seek, in some other part, its necessary nourishment, and then 

 appears to form itself into large or small shoals, which, at first, just as 

 if it, as yet, had not quite weaned itself from its former erratic ways, 

 still roams about undecidedly for a while in the vicinity of land. It is 

 then eagerly sought for by voracious fish, and especially by the Cod 

 which come in just at that time in shoals, and destroy them by the 

 million. It A\ould fare badly with these defenceless small fish, did not 

 instinct finally teach them to seek shelter in the quiet bays and creeks, 

 where, close into the beach, they find sufficient nourishment, and protec- 

 tion from their persecutors, amongst the sea-weed that grows there.« 



Sars next describes how these small fish, as they grow and became 

 bigger, gradually move out to deeper and deeper water. Whilst they, 

 as small young fish, can be seen from the land, or from boats, in great 

 shoals in shallow water, the larger fish prefer deeper water, and are to 

 be found in the following various stages of development which are 

 called by the fishermen »Smaagjed« (Codlings), »Skreiemort« &c. &c., 

 until they, at an age of 3 to 4 years, forsake the coast entirely, and 

 migrate to the open sea, returning, during the Winter, for the purpose 

 of spawning off the coast. 



Only a few remain behind »Taretorsk« (Rock Cod) and they appear 

 to form a coastal species which, in minor characteristics, differ from the 

 true cod. 



From this representation we may conclude that the fry of the Cod 

 originally live as coastal fish, and only gradually adopt the habits of 

 the adult fish, as fishes of the ocean. 



