42 



bottomstages of the plaice were uot ttikeii at all during 1904 iu the true Baltic, 

 in the eastern part of the western Baltic, in the eastern Great Belt nor in the 

 southeru Kattegat. The bottom-stages of the plaice have thns a similar, character- 

 istic distribution to those of the cod, they are abseut from the eastern side of the 

 Belt Sea. We certainiy found plaice youug iu the Sound in September 1904, but 

 only a few in comparison with the time speut on the investigations, and we found 

 none there in June. 



If we look at Tab. G in order to compare the distribution of the plaice 

 eggs, pelagic young and bottom-stages, we find that the area narroivs as the transition 

 from egg to pelagic young and thence to hottomstage goes on. Plaice eggs are found 

 in all the Danish waters, when sought for at the right time, eveu in the true 

 Baltic. The pelagic young were not found during 1904 in the true Baltic and the 

 Sound*. In the western part of the western Baltic we took oiie pelagic specimen 

 of plaice; the bottom stages were only found on the south coast of that region. 

 From the Great Baltic we have in all 12 pelagic plaice young; the bottom-stages 

 were onlj' found on its western coasts. In the southeru Kattegat, south of Anholt, 

 we took two pelagic plaice young, the bottom- stages were not found south of a 

 line through Anholt. 



To jndge from our 1904 investigations, there seems a certain resemblance 

 between the Skager Rak and western Baltic as regards the quantities of pelagic 

 plaice young. The developiiieilt however does uot proceed on parallel lines in the 

 two regions, being somewhat later in the western Baltic. This is shown by the 

 later appearance of the eggs, pelagic young and bottom-stages. To illnstrate these 

 conditions I may give some journal extracts with the remarks I have noted there 

 w hilst the investigations were in progress. 



D. 21 — 4—04. Thyborøn Channel. At Thyborøn to-day after persistent .search with the 

 "bobinet" net we succeeded in tinding 5 metamorphcsed** plaice young, ca. 15 mm. long. 



D. 27 — 4 — 04. N. of Frederikshavn'.s harliour. We went out in a small sailing boat to 

 the nortli of Frederikshavn'.s haibour and searched for about two hours -with the "bobinet" and 

 "haif-moon"*** net.f, both in shallow water and somewhat deeper from the boat. With the 

 "half-moon" net in ca. 1 foot of water we got one metamorphosed young plaice, 11 mm. Of 

 I group we took in all 7 specimen.s of 5 — 6 mm. Earlier investigations of the Biological Station 

 have shown, that great quantitie.s of the metamorphosed young plaice can be taken in a short 

 time at this spot in May — June. The single specimen we succeeded in taking may therefore be 

 regarded as a torerunner of the wandering in to the coast, whilst the majority of the O group 

 must be still in deeper water, so far that is as they are hatched, which I assume to be the case, 

 as the plaice eggs so numerous in the previous month are not now to be found. 



D. 28—4—04. Skaw lightship in S., 1'/., miles, 40 fm. (Tab. 1, Skager Rak). In two 

 hauls of altogether 25 minutes with the young-flsh trawl in intermediate layers down to ca. 12 fm. 

 we took yi plaice young, most of which were still symmetricai, whilst in some the changing over 

 of the eye had begun; the left eye was still on the left side of the head in all however except 

 one of 14 mm. which had the eye on the ridge but still looking to the left. In the same haul 

 was taken a large number of other young, chiefl>- of cod and haddock. Most plaice were taken 



* Nor did we find pelagic plaice young in the Lim Fjonl in 1!)04 (see Tab. 1, Lim 

 Fjord), though we eagerly souglit for them with the young-lish trawl at the end of April. We 

 found no plaice eggs either. 



** See footnote p. 18. 



•** "Half-moon" net may be regarded as a "bobinet" net without shaft, which is 

 dragged after one in wading or after the boat in depths a little greater. 



