576 KEPOET OF COMMISSIONER OF FISH AND FISHERIES. 



THE SPAWNING. 



The end of March is generally considered the time when the majority 

 of the codfish spawn. Physical conditions, however, exercise a great 

 influence on the spawning process; thus, it may be retarded by long- 

 continued cold weather and accelerated by unusually mild weather. It 

 is, therefore, difficult to set any definite limits for this time, all the more 

 as the different schools by no means all spawn at the same time. Some 

 schools may be spawning while others are just coming in, and long 

 after the time when the first begin to leave the coast, there are some 

 schools which have not yet spawned. This may easily be observed in 

 the fish which are caught, for it is not a rare occurrence that on one and 

 the same day fish are caught with entirely loose roe and some whose roe 

 is as firm as at the beginning of the coming-in season. The last-men- 

 tioned fish certainly belonged to a school which had but recently come 

 in, while the former must have been near the coast for some time, as the 

 schools coming in first always spawn before those coming in later. 



The earliest spawning which I observed during the last Loffoden fish- 

 eries was toward the end of February far up the Eastnaes fiord. By fish- 

 ing with a fine net on the surface of the sea I caught some small, 

 completely transparent globules floating on the water, which I at first 

 took for some very low species of aquatic animals, as I was entirely 

 ignorant of the peculiar spawning process of the codfish, to which I shall 

 now refer. I had in former times heard fishermen say that the roe of 

 the codfish could be seen floating in the water, and that at certain sea- 

 sons it filled the sea to such an extent as to make the water appear 

 quite thick 5 but as this was in such direct opposition to anything I had 

 hitherto known of the spawning of fish, I could not but suppose that what 

 had been taken for spawn was in reality nothing but those lower aquatic 

 animals which (as is well knov.a) often fill the sea. The roe of codfish 

 I never looked for, unless brought up from the bottom. The microscopic 

 examination of the above-mentioned globules showed beyond dispute 

 that they were eggs, although they were too little developed to decide 

 whether they were fish-eggs. Gradually these eggs, floating about freely, 

 became more numerous, until, about the end of March, they filled the 

 sea, so I could get as many as I wanted. I now succeeded in following 

 their development step by step until the tender little fish slipped out of 

 the shell and swam about in the water. 



It is certain that these eggs were really the spawn of the codfish, and 

 of no other fish, to judge in the first place from their enormous number, 

 and in the second place from comparisons which I made between them 

 and roe, which about this time could, by a gentle pressure, be extracted 

 from spawners. 



This roe did not sink to the bottom, but floated on the water like that 

 which I had first observed. This peculiarity of the roe of the codfish, 

 to which no parallel is found in any other fish, must be caused partly by 



