THE SPAWNING AND DEVELOPMENT OF TIIE COD-FISH. 221 



NOTE. 



The following note, in continuation of the preceding investigation, 

 from Professor Sars to Professor Agassiz, was published by Mr. Theo- 

 dore Lyman, in the report of the Massachusetts commissioners of fish- 

 eries for 1871 : 



" It was my intention to continue the investigation of the young of 

 the winter-cod, which I had pursued the previous year. I then showed 

 that the fish often considered as a separate species, and known on the 

 northwest coast of Norway by the names of smaagjed, tarefisk, and 

 griindfisk, is nothing but the young of the winter-cod. I further ob- 

 served that the great variations in color are only the effects of different 

 bottom and different food. 



" It was my task this year to follow the further development of the 

 smaagied during the summer. The conditions were now quite different ; 

 for whereas during the winter I could, from a boat or from the beach, 

 easily study my objects, now the fish had retired to the deep water and 

 could only be got by hook and line — a difficult matter, by reason of the 

 scarcity of bait, for the muscle rocks had been ransacked by the winter 

 fishermen, and herring were not to be had. Beginning on the 20th of 

 May, at a place called Skraaveu, I set my line in 20 to 30 fathoms water, 

 in the sandy channels of the outer holms, but got only fish too large to 

 be yearlings. I then set in the ' sculls ' near the rocks, and took great 

 numbers of small cod, corresponding perfectly with the tarefisk, and 

 which were colored of a brownish-red by the tare or rock-weed, (Lamin- 

 aria.) These sculls are very dangerous to approach, especially in the 

 winter-time, and are characterized by a periodic ground-breaker. The 

 sea will appear perfectly tranquil for a time, when suddenly there will 

 arise gently, over the scull, a low, broad pyramid of water, which as 

 gently descends, and again the surface is unruffled. The wary fisher- 

 men mark well these upliftiugs, and keep the boat away from them. 

 Presently you observe that the pyramid has again risen, but with in- 

 creased size and with smoke curling from its apex; there is a sort of for- 

 ward pushing motion and a sullen roar, and in an instant the sea rises in 

 a vast, glittering, green bank, capped with devouring foam. With a 

 fearful crash it precipitates itself to the very bottom, leaving a great 

 circle of white froth. Your boat, safe in the offing, is lifted high on a 

 huge wave, and the distant thunder on the beach announces that the 

 great breaker has struck. The hapless boat that gets caught over one 

 of these sculls is dashed in a hundred pieces against the rock bottom. 

 These violent periodic ground-breakers are what attract the smaagjed, 

 for they wash out the small crabs from their hiding-places among the 

 sea-weed, and the young cod, dashing forward with the returning sea, 

 devour them greedily. I thought now I should get plenty of yearlings 

 on the sea-weed ground during the whole season, but I was mistaken. 

 Toward the end of June they almost wholly disappeared from that lo- 



