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an annual series and shows exactly how much the plaice (i. e. the whole 

 stock) grows on an average ever} 7 year. 



Another question is, whether I have always in every single case 

 succeeded in distinguishing between these annual series; I hope in future to 

 be able to examine this closer. The method I hope and believe, will lead 

 us to the goal at length. — 



It appears to me that the groups — 1 — 2 etc of the plaice must 

 be pretty well separated in nature, when we can point them out by merely 

 fishing promiscuously and making a summary of the results of these draughts. 

 For besides distinguishing between the sexes we ought also properly, when 

 we want such a summary, to fish the same number of specimens of each 

 annual series, in order not to efface the boundary lines between them. 



This is of particular importance where the various sizes within the 

 annual series, as the case is with the plaice, are found on different depths, and 

 it is clear that if we would fish but little on shallow and on deep water, but 

 very much on the intermediate depths, we could efface all difference be- 

 tween the series, in many cases on account of the too great influence of 

 exceptions. T have therefore generally tried to avoid a too great crowding 

 at one place in the row, and practice lias shown that it is easy to avoid if. 



Among other fishes, for instance the eel-pout, where all annual series 

 may he fished in the same draught, this difficulty does not exist at all. 



We have thus followed the plaice through its first year (the 0-group). 

 into the second (the 1-group), nay, into the third (the 2-group), and have 

 seen it withdraw more and more from the shores. 



While the 0-group, so to speak, was completely missing in the Baltic, 

 there being scarcely any specimens under 3 inches (there Avere 4 exceptions) 

 (see table VII & VIII), the 1-group and 2-group are richly represented (see 

 table VII & VIII). Column 10, table VII, is a summary showing both 

 groups; the point where they meet is perhaps a little lower than in the Kattegat, 

 viz. a little under 6 inches against a little over 6 inches in the Oattegat. — 

 The 1-group is, with very few exceptions, not represented at Born- 

 holm (table VIII), from which we can draw the conclusion that the plaice 

 does not go there till it is more than two years old. The many seine- 

 draughts indicate this very decidedly, and if we study closely the localities 

 in table VII, it will be seen that the farther we go west of Moens Klint 

 the more numerously is the 1-group represented, so that Lieutenant Hansen, 

 who undertook these measurements, arrived at the conviction that the 

 plaice immigrate into the Baltic through the Great Belt south of Gjedser, 

 a result which also to me seems very likely. — 



