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Funen, Sealand, and as much of the Baltic as Ave have hitherto explored, 

 is an incontestable fact. 



Whether these circumstances are the same every year, of course I 

 cannot tell; there may be some variation, I dare say; this is indicated by 

 the occurrence of the fry at Famo 1891 and its disappearance in 1892 and 

 93, and I have moreover been informed by Dr. Apstein, at Kiel, that he 

 has been unable to find such fry this year at Eckernf0rde-Fjord, while they 

 had specimens from former years, partly from Kiel, partly from Neustadt. 

 Professor V. Hensen had been kind enough on my request to ask Dr. Ap- 

 stein to examine this question*). 



Although we must thus suppose that the distribution of the 0-group 

 is not quite the same every year, I cannot doubt it will prove to be the 

 rule, that such small plaice (under c. 2 — 3 inches) are not found in great 

 numbers (except perhaps at a feiv places) on the shores of the Baltic, and that 

 the numerous stock of plaice here (for instance at the isle of Maen, see table 

 VIII) must consequently be born somewhere else and afterwards immigrate into 

 the Baltic Sea. 



I say that the stock of larger plaice is numerous in the Baltic, and 

 shall for the further elucidation of this matter refer to »Rersearch No. 110«, 

 during which in one draught with plaice-seine off the isle of Moen were 

 caught 594 plaice, besides 487 Pleur. limanda and a few other fish, in all 

 1087 specimens of fish in this one draught. 



When we hear, moreover, that the fry of other flat-fishes' (Pleur. 

 ftesus, Rhombus maximus & Icevis) which in the Cattegat lives together with 

 the fry of plaice on the shores, during these researches was found also in 

 numbers on the Danish shores of the Baltic, and that it was only the fry 

 of the plaice which was wanting here, this must be looked upon as a 

 further proof of the correctness of the statement. (How to distinguish 

 the fry of the various species will be mentioned afterwards). 



At another place I have shown that certain animals which in the 

 Cattegat are littoral occur in the Baltic on deep water, though certainly 

 also as littoral forms, for instance Cardium edule. 



*) Mr. 67. Duncker has afterwards kindly informed me that he found, in 1893, the 

 tender fry of plaice smaller than 2 inches *in numbers* in the cove of Neustadt 

 off Liibeck, so that there can be no doubt that some of the great numbers of eggs 

 which in spring are found in the Baltic may be developed there, at any rate in 

 certain years. Till further researches into this matter I must suppose however, on 

 account of the almost total want of fry on the Danish shores of the Baltic, that this 

 does not take place so generally that we can believe the Baltic to have a stock 

 of plaice of its own, which really breeds there in numbers and as a rule. 



