THE COD FAMILY 285 



July 5th he made the discovery that the little fish were shelter- 

 ing themselves under large jelly-fishes which were very abundant, 

 and he caught numbers of them. He found that they practised 

 this habit for the sake of the crustacean parasites of the jelly- 

 fish, specimens of which he found in the stomachs of the fish. 

 The largest young cod which he caught at this time measured 

 li inches in length and showed already distinct colours, five or 

 six dark streaks running round the body, while the sides showed 

 a silvery or golden gloss. 



The next year, on August 3rd, Sars caught young cod-fish 

 swimming in shoals in one of the curious streaks which are 

 formed in the sea by currents, and in which floating weeds, jelly- 

 fishes, and other floating animals often collect in quantities. 

 These fish were about 2 inches in length, or a little more. The 

 fins of the perfect fish were fully developed in these, and also the 

 barbel under the chin, and apparently the scales. In colour 

 they were marked above with lines of square spots of a reddish- 

 brown, the sides being silvery and golden. At this stage then, 

 when the cod are only about 2 inches long, what I have called 

 the second stage of their life is over, and they have reached in 

 all important respects the condition of the perfect fish. 



The cod at the Lofoten Islands spawns chiefly in March and 

 April, and these most advanced young were found at the very 

 beginning of August, so that they could not be more than five 

 months old. But even at the earlier stage, at the beginning of July, 

 when only i^ inches long, and found frequently sheltering under 

 the jelly-fishes, they have practically completed their transfor- 

 mation, and these were found only four months after the com- 

 mencement of the spawning period. It must be remembered, 

 however, that in the cold water of the Lofoten Islands cod eggs 

 take a long time to hatch. Sars found in vessels kept on shore 

 that the egg hatched in eighteen days, and in the sea the water 

 would be colder, so that we must take off about three weeks for 

 the period within the egg, and we arrive at the conclusion that 

 the little cod, li inches long, which had gone through their 

 transformation, were little more than three months old, if 

 spawned at the beginning of the spawning period, while if they 

 came from eggs shed in April they were not much more than two 

 months. 



The development of the cod has been also studied by Professor 



