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I imagined therefore the certainly rather far-fetched possibility, that 

 the fry of the plaice perhaps might live on deep water in the Baltic, though 

 it is particularly littoral in the Cattegat, and with the assistance of the 

 »Hauch« I explored the deep with Ammodytes-seines in order to see whe- 

 ther it was living there. It was not; but during these explorations quite 

 small specimens of Pleur. limcmda were found on deep water, to be sure 

 only a few (14) specimens, yet enough to confirm ni}- supposition in Re- 

 port from the Biol. Station III, 1882«, p. 16, that it must be so. — 

 Crop. » Research No. 159« *). 



Having thus mentioned the geographical distribution of the 0-group 

 east of the Skaw, we pass over to the next question, viz. its age. 



This question is closely connected with that of the spawning-season of 



*) Note. It cannot here be left, unmentioned that G. Winther in >Bidrag til Kund- 

 skaben om Fiskeriet ved Torbsek, p. 314. Nordisk Tidsskrift for Fiskeri. Ny 

 Rrekke. 1. Aargang. 1874«, speaks of the occurrence of the plaice in our seas, 

 and among other things says that its fry is found in the Sound, and that 

 it, > scarcely half an inch long, is found in the month of June everywhere <. 

 etc. He does not tell how it can be distinguished from the fry of Pleur. 

 flesus which is living there, loc. cit. p. 315, so it is not impossible that he has 

 mistaken one species for the other; -scarcely half an inch< is too short for a great 

 number of plaice in the month of June. His statements as to the age of the plaice 

 are not supported by reasons, and whether right or wrong, therefore, they are useless 

 in a scientific discussion. The same applies to some of his other remarks respect- 

 ing the biology of the plaice; many of them, evidently, are founded only on loose 

 statements of fishermen, and are certainly quite wrong, though they often may be 

 proved to originate in some (often misunderstood) reality. — In > Motrins und Hew eke : 

 Die Fische der Ostsee. Aus IV. Bericbf der Commission zur wissensch. Unters. 

 Kiel' is, under the plaice, a picture of a young flounder in its pelagic stage, which 

 to judge from its form, must surely be a young Bhotttbus; this is made more likely 

 still by the statement >So tritt't man sie namentlich im Mai und Anfang Juni bei 

 ruhigem Wetter an der Oberflache an-; for 1) this time agrees very well with the 

 time for pelagic fry of Rhombus; 2) it agrees but badly with the time for the 

 pelagic fry of the plaice; 3) I never saw the latter swimming about in the 

 surface of the water, though perhaps they may do so at times. 



How these young ones according to the statements of the above authors can 

 be seen in an aquarium developing themselves into flounders turned to the right, 

 is a riddle to me. Probably there is some mistake of identity; till this is cleared 

 up I cannot help doubting the correctness of these gentlemen's statements with 

 respect to the fry of the plaice in the Baltic Sea. That, on the other hand, the 

 fertilized eggs of the plaice are to be found there is well known from Henseris 

 excellent researches. 



If we would look for information about the fry of the plaice in the older litera- 

 ture, we should probably find various observations on this question ; but I doubt 

 whether it would be worth our while to do so, and leave it to others who have 

 more leisure time than I have, taking into consideration only the later piscatory 

 literature on this subject. This is already rather extensive, even when we do not 

 count all that which treats the matter in an unscientific way and only gives state- 

 ments unproved by any precise and positive huts. 



