— 225 — 



In these circumstances it is evident that the best chance of making anything out of 

 a comparison is obtained by first of all taking note of the data from the regions, where 

 a fishery for the elvers takes place, as it is just there where an interest in their arrival 

 is taken that the people naturally pay more attention to when they begin to appear than 

 at other places, where no one troubles about them. In order to give a view over the 

 matter I have marked on the Chart the places on the Spanish, French and British coasts 

 where an elver fishery is carried on ; different signs indicate the months in which the 

 fishery begins at the various places (see the Chart, Plate XII, where the area within which 

 the fishery is carried on is marked and the names of the places concerned are underlined). 



We see from this that the elvers first appear at Spain and far south at the French 

 west coast (at Bayonne), namely, in the last months of the year (October to December), 

 somewhat later further north on the French west coast in January, still more to the north 

 in February and in the Channel in February — March. In South-West England (Bristol 

 Channel) the fishery also begins in February or rather in March. 



It might really seem therefore as if the geographical latitude was the determining 

 factor for the arrival of the elvers, but no good case for this could be made out ', as we 

 have indeed found the larvae as far north as the Faeroes and, as will be seen shortly, 

 there is an explanation based on our "Thor" investigations with regard to the distribution 

 of the Leptocephali in the Atlantic which undoubtedly comes nearer to the truth. 



From the previous sections we have seen, that all the available information indicates 

 that if not all yet the great mass of the eels of North Europe spawn at the same period 

 of the year. It must therefore seem evident beforehand, that the distance of a coast 

 from the spawning places must especially have a determining influence on the period at 

 which the elvers begin to appear on that coast. In order to test how far the available 

 data could be brought into agreement with the results as regards the spawning places of 

 the eel, which the "Thor's" investigations had given, it was naturally of the greatest im- 

 portance to obtain trustworthy information as to the time of appearance of the elvers on 

 the Irish coasts. As can be seen from the Chart, Plate X, we had nowhere found 

 the eel larvae {Leptocephalus brevirostris. Stage l) nearer land than just off the Irish 

 coast. 



As I could find no serviceable data in the literature concerning the ascent of the 

 elvers at Ireland, I applied to the Director of the Irish fisheries investigations, Mr. E. W. 

 L. Holt of Dublin, who with the greatest kindness interested himself in the matter and 

 procured me a great deal of information, the importance of which for the present question 

 will readily, be seen^ I give the information here just as it was sent me: 



1 That Stage 5 tias not hitherto been found in the waters to the west of Great Britain before November 

 though the same stage occurs in September — October on the Spanish north coast, is most probably due to 

 lack of observations, perhaps also to the circumstance, that the higher surface-temperatures of the water at 

 Spain cause the last part of the development (to Stage 5), which is passed in the surface layers, to proceed 

 more quickly than further to the north. 



2 Mr. Holt's information agrees specially well with the information I have received through the Danish vice- 

 consul Mr. John Foley in Tralee which is mentioned on p. 203. According to Mr. Foley the elvers are fished 

 and eaten at several places in Kerry in South-West Ireland, as at Castlemaine on Dingle Bay, on the River 

 Feale and in the Tralee district. The fishery according to him takes place in January, in which month I have 

 also received a sample of cooked elvers from there. 



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