— 50 — 



not a single j'oung pollack was taken, neither late in April, late in June nor in August 

 or September, would perhaps indicate that the depths in this the south-eastern and eastern 

 parts of the North Sea were not sufficient for the reproduction of this species. The depths 

 on this line varied from ca. 20—38 meters. 



5. The Channel 



Of the regions investigated by us the Channel is the one in which the pelagic fry of 

 Gadus poUachius occurs with the greatest regularity in our hauls with the young-fish trawl. 

 Chart II shows that all the stations in the Channel in the end of April and beginning 

 of May 1906 gave positive results, which is in contrast to the conditions in the North 

 Sea where we obtained no pelagic fry of the pollack on the way from Esbjerg to Dover. 

 These fry appeared as soon as we entered the Channel and increased in numbers as we 

 went westwards, so that the largest number, 15 specimens per ^h hour's haul, was taken 

 in the neighbourhood of Plymouth. Most of the specimens taken were small, 1 cm. or 

 thereabouts, so that they were presumably not more than 1 — 2 months old and had thus 

 not been spawned earlier than in March (a few of the largest possibly in February). 



As mentioned above, Gadus poUachius was the only species of the group G. saïda, 

 callarias, virens, poUachius, whose pelagic fry we found in the Channel. This result 

 agrees extremely well both with earlier observations and also with the contents of some 

 hauls with the pelagic and bottom tow-nets, kindly sent me by Dr. E. J. Allen of Plymouth, 

 in which of this group of Gadus species only G. poUachius occurs. Further, in the lists 

 published by Holt and Scott (1. c), the eggs of the pollack are stated to occur (in the 

 neighbourhood of Plymouth) in February and March, whilst the pelagic fry are found in 

 April and the whole of May, as also in the first half of June, after which time they do 

 not occur in the pelagic hauls'. The majority of the pelagic fry were about 1 cm. at the 

 end of April and in the first half of May, at the end of May and beginning of June 

 about 2 cm. 



As we did not make investigations on the coast in the Channel, I may give here the 

 contents of some few of the samples of the bottom stages from the neighbourhood of Ply- 

 mouth, which were sent me by Dr. E. J. Allen. 



1. Cawsand Bay, 20. June 1905. Shrimp trawl 

 Gadus poUachius: 38. G.luscus: 2 (S'/s, 4 cm.). G.minutus: 4 (4, 4, 3Vä, 3^/2 cm). 

 cm. 5 4 3 



No. 4 8 22 4 

 2. Whitsand Bay, 6. July 1905. Shrimp trawl. 



Gadus poUachius: 48. G.luscus: 2 (5 cm.). G. minutus: 3 (4—6 cm.), 



cm. 6 5 4 3 



No. 4 7 U 17 6 3 



These two hauls, which are typical of the whole material I have examined from Ply- 

 mouth, are sufficient to show that the young bottom stages of the pollack occur here in 



■ Whilst Holt and Scott's determination of the pollack eggs can scarcely be quite certain, as these 

 are and were not sufficiently well known, there is no doubt of the correctness of their determination of 

 the pelagic fi-y. Whilst preparing my monogra])h on the postlarval Gadus-yomig, I Avas given the op- 

 portunity of examining the samples of Holt and Scott, and could in all oases confirm their determinations. 



