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even so late as I he summer. These elvers in addition to being found on the 

 Mediterranean coasts also occur along all the coasts of Western Europe at the Faeroes 

 and Iceland, along the greater part of the Norwegian coasts, in the North Sea, in 

 the Skager Rak, Kattegat and the Belts and perhaps here and there on the Baltic coasts. 

 The eel-fry which generally ascend the rivers of the inner Baltic are not however 

 "montée" in the sense in which I use the word, but larger (older) individuals (according 

 to the Swedish investigations of Dr. Trvisom they are 25 to 43 centimeters in length and 

 they ascend in the period from July to September). On the other hand it must be 

 remembered that the ascent of such large or even larger eel-fry may also occur at other 

 places besides in the Baltic (for example, in Scotland, England, Norway, Denmark, West 

 coast of Sweden etc.). 



There is also a second condition in addition to the first which has to be considered, 

 when conclusions are to be drawn from the size, appearance and time of arrival at the 

 various places with regard to where they come from, namely, that until the metamor- 

 phosis is quite completed the fry decrease in length and only later, like the young 

 of other fishes, increase in size with age. This is a rock on which more than one 

 author engaged with this question has stranded, but in North Europe this fact has for 

 the first time been made sufficiently clear through A. C. Johan sen's researches. 



In spite of the various difficulties in the way of comparing the reports to hand, so 

 much certain information has already been obtained that it is possible to trace out the 

 main lines of a picture which it is to be hoped future investigations will soon complete. 



I shall here consider two conditions chiefly, in the first place the magnitude of the 

 montée-phenomenon on the different coasts and secondly the time at which this takes 

 place. 



With regard to the first (/5) the magnitude of the montée ° phenomenon, it 

 appears from the material without any possible doubt, that far greater quantities of 

 tiny elvers ascend on the true Atllantic coasts of Europe than on those of 

 the North Sea, Norwegian Sea or Baltic. This is remarked at once from the 

 first reading of the reports from the different places, and further there are definite facts 

 which show it. Thus, an extensive fishery for eel-fry to use them as food has 

 only developed on the true Atlantic coasts, that is, the coasts directly washed by the 

 warm water of the Atlantic. The Chart, Plate XII, shows the places where such a fishery 

 is carried on and one can see that these lie on the Spanish coast, the French west 

 coast, partly also the north, the south west part of England and the west 

 and south coast of Ireland. On the other hand such a fishery is not known, either 

 on the coasts of the Norwegian Sea or North Sea including . the Baltic, and in my opinion 

 this must be ascribed mainly to the fact, that on these coasts no such great quan- 

 tities of ascending elvers occur as would enable a fishery on a large scale to 

 develop. 



A direct comparison of the quantities of elvers at the different places shows also, 

 that this explanation must be right. We may choose and compare the conditions at 

 three points, for example. A: Bristol Channel in south-west England, B: the 

 Danish coasts (of both North Sea and Kattegat) and C: the Swedish Baltic coasts'; 



I I choose the Bristol Channel as somewhat definite information is available from there, and the Danish 

 coasts because the conditions there are naturally well-known to me. 



