— 2U — 



that the elvers on the Jutland west coast begin to migrate into the fresh water at 

 the end of April or beginning of May. In iy05 we found them in quantities at Esbjerg 

 in the latter half of April in the brackish water, but it was only on May 2nd that they 

 were taken in the stream, although they had previously been sought for there. When I 

 was in Ribe 1899 I saw the young eels in the stream first on May 7th, but they were 

 then taken in hundreds. When the water retreated at ebb-tide, cakes of dead eel-fry 

 were formed. On two earlier occasions when I have searched for the small eels in the 

 streams at Ribe, I found no glass-eels, but small, thick, dark-coloured, young 

 eels. On February 2öth 1899 for example I foond 9 young eels of the following length 

 buried in the sand: 65, 65, 68, 70, 72, 73, 73, 86, 96 mm. Even the smallest of 

 these must be l year older than the glass-eel. On March 19th, 1899 I found 

 two specimens of the following length: 75, 105 mm." 



During February 1906 one of the "Thor's" fishermen, Tarben Tarbensen (the same 

 man who had collected the young eels on the west coast of Jutland in the spring and 

 summer of 1905) on Dr. A. C. Johansen's initiative searched for the young eels near 

 Esbjerg (on the west coast of Jutland) at the following places: 



(1) Coast, N. W. from Esbjerg harbour; Febr. I2th, 1906, searched with shrimp shove- 

 net for 2 hours, 1 foot depth. No eel-fry. 



(2) Same place; Febr. I2th, 1906, shrimp shove-net for 2 hours in l foot depth. 

 No eel-fry. 



(3) Coast, S. E. from Esbjerg harbour; Febr. l6th, 1906, shrimp shove-net 1/2 hour. 

 No eel-fry. 



(4) Stream at Maade tile-works, S. E. from Esbjerg; Febr. i6th, igo6, shrimp shove- 

 net for 2 hours. No transparent eel-fry, but 27 dark young eels of following length 

 found: 68, 69, 71. 76, 76, 76, 78, 81, 81, 82, 83, 83, 84, 85, 86, 87, 91, 92, 93, 97, 99, 

 99, 102, 102, 105, 108, 119. 



The result was therefore, that up to the middle of February the eel-fry of the pre- 

 vious year cold not be found, but however those of the earlier year. 



The ascent of the eel-fry of the most recent year's group has thus not been ob- 

 served on the coasts of Denmark before April, and such a large series of concordant 

 data is to hand, that there can scarcely be any doubt that the ascent of the great mass of 

 elvers does not begin much earlier than this month. 



Sweden. A distinction must be drawn here between the Swedish west and east 

 coasts, as the conditions are so extremely different on these coasts. 



NiLSSON (Skandinavisk Fauna, IV, 1855, p. 675) says even so early as that date 

 that on the west coast: "enormous shoals of small eel-fry come up from the sea into 

 the rivers in the months of May and June. These eel-fry are then two or three inches 

 long and as thick as sail string. Instinctively they seek the running water and go up in 

 this against the stream. In this way they penetrate so far up as is possible for them 

 and not only in the large rivers but also in the small outflows until they find a 

 suitable place to live. They ' can even creep up the wet rocks on the sides of water- 

 falls, where these are not too high" . . . (note") "but over the TroUhättan falls the 

 eel-fry could not pass and this species therefore was not found in Lake Wenner or any 

 of the water-courses, which open out into the basin of this large inland sea. It was 



