- 102 — 



eggs were first taken in May in the most northern part of the North Sea (between the 

 Shetlands and Norway) in water of ca. 7°. 



On the basis of these observations wo may conclude, that the ling only spawns 

 in the northern part of the North Sea and in the Skager Rak, but not in 

 the shallower southern and central parts. And if we compare the conditions 

 here with those found elsewhere, e. g. in the Channel, there can be no doubt that it is 

 the small depths in the southern and central parts which are the determining factor in 

 this regard. But even in the northern part of the North Sea, with exception of the north- 

 western, and in the Skager Kak, the numbers are not large as in the neighbour- 

 ing parts of the Atlantic. In the Skager Rak we had ca. 35 stations in June and 

 July 1907 with about 100 hauls at various places everywhere in this water, but only ca. 10 

 pelagic fry of the ling in all were taken, which clearly shows that no great quantities of 

 the fry are spawned in the Skager Rak. 



5. The Channel 



As the Chart shows, the fry of the ling were only found in the most western, deepest 

 part of the Channel and even then in small quantity (2 specimens per half hour). At all 

 our stations in the remaining parts of this region the ling fry were quite wanting. As 

 the temperatures in the Channel, to judge from the conditions elsewhere, are sufficiently 

 high to permit of the ling spawning, we must conclude that the reason for the absence of 

 the fry in the eastern part is to be found in the shallow depths there. 



That the ling spawns in the deeper western part of the Channel (and naturally in 

 the waters outside this), although not in great quantity, is shown by our catches of the 

 small fry there in the beginning of May 1906, and it is also shown by one of the samples 

 sent me from Plymouth Laboratory, which was taken with the young-fish trawl in Ply- 

 mouth Sound on May 22nd 1907 in a haul of half an hour near the bottom (depth 15 — 

 16 fathoms) and contained one small ling less than 1 cm. in length. It seems from all 

 the data that but a slight production of the ling fry takes place even here in the western 

 part of the Channel, which is also in agreement with the fact that Holt and Scott's often 

 cited lists do not mention the ling eggs or larvae, nor is the ling mentioned by Holt (1. c. 

 1897 — 99) as spawning in the "south-western district". 



As the pelagic fry have been proved to occur in the Channel, we see that they are 

 found in fact over a continuous stretch from the northern part of the North Sea west 

 and south round the British Isles. On the other hand there is no direct connection be- 

 tween those occurring in the western part of the Channel and those in the northern part 

 of the North Sea through the Channel, as they are separated by the shallow southern part 

 of the North Sea and the eastern part of the Channel, just as is the case for other species 

 which do not spawn in quite shallow water, e. g. Gadus œglefinus and Esmarhi. 



6. Bay of Biscay 

 We took the small fry of the ling off Brittany on the boundary of the Channel and 

 the Bay in May, but we did not find them further south in the Bay. 1 conclude there- 

 fore that it is only or almost only in the northern part of the Bay that the ling spawns 

 and even there not in very large quantities. This seems to agree with what Moreaü 



